Flexible pressure sensor based on CNTs/MS composite for health monitoring - Jialing Xia, Linze Li, Weiquan Feng, Wen Zeng, Qu Zhou (Colloids and Surfaces B: Biointerfaces, 2026)

High-performance flexible tactile pressure sensor via MXene/Bi/tissue paper composite films for wearable electronics - Leini Wang, Yinsong Guo, Chengtian Wei, Qiaoqiao Zhang, Ning Wei, Wei Zeng (Colloids and Surfaces B: Biointerfaces, 2026)

Flexible pressure sensor with femtosecond laser-induced hierarchical micro/nanostructures for physiological signal monitoring and tactile object recognition - Fanming Liu, Hailin Yang, Wu Zhang, Meng Zhang, Chengyun Zhang (Measurement, 2026)

All organic PVDF-based polymer composite for capacitive energy storage engineered via structural evolution - Hanxiao Gao, Chenyi Li, Guanxiang Zhang, Yutie Gong, Sinan Lin, Yang Li, Xiao Zhang, Junyong Lu, Huamin Zhou, Yang Liu (npj Flexible Electronics, 2026)

Interfacial dipolar channels of high-dielectric BaTiO3/PVDF composite film enable high-rate and stable lithium batteries - Luozhi Mo, Enmin Xu, Yingke Zhou, Xuan Liu, Zhe Cheng, Xiaohui Tian (Chemical Engineering Journal, 2026)

Leaf vein-inspired ethyl cellulose mediated dual-network design for enhanced energy storage in PVDF-based all-organic polymer dielectrics - Linsheng Yang, Hongwei Lu, Bengang Li, Shijia Yang, Weitao Su (Carbohydrate Polymers, 2026)

High‐Entropy Lead‐Free Relaxor Ferroelectric Ceramic with Wide‐Temperature‐Range Self‐Powered X‐Ray Detection - Yufei Song, Jiangtao Fan, Feifei Guo, LingXiang Wang, Yifan Hu, Zheng Cheng, Zeliang Gao, Zhanggui Hu (Advanced Materials, 2026)
ABSTRACT Sensitive and stable x‑ray detectors are essential for low‑dose medical diagnostics. Achieving wide‑temperature operation in materials remains a key challenge for enabling thermally stable, self‐powered x‑ray detection. Herein, a high‐entropy lead‐free relaxor ferroelectric ceramic, 0.85Bi 0.47 Na 0.47 Ba 0.06 TiO 3 ‐0.15Ca 0.7 Ho 0.2 Ti 0.75 Ta 0.2 O 3 (BNBT‐CHTT), is fabricated first. The unique entropy‐stabilized polar nanoregions (PNRs) endow the system with high resistivity and robust spontaneous polarization, underpinning exceptional self‐powered performance across a broad thermal window. Under 70 keV x‐ray irradiation, the detector exhibits excellent stability from 25°C to 185°C, delivering record‐high specific sensitivities of 1117.44–1223.55 µC Gy < jats:sub>air −1 cm −2 , self‐powered sensitivities of 597.28–699.78 µC Gy air −1 cm −2 , and low detection limits of 38.7–160.6 nGy a i r s −1 . Notably, distortion‐free x‐ray imaging is demonstrated at 185°C under zero bias, validating the material's practical utility. This work highlights the potential of high‐entropy relaxor ferroelectrics to overcome key limitations of existing detectors and provides a robust platform for next‐generation, low‐power, wide‐temperature‐range x‐ray detection and imaging technologies.

Ultra-high piezoelectric properties of BiFeO 3 –BaTiO 3 lead-free piezoelectric ceramics enabled by a one-step sintering process - Shiyuan Zhang, Xianxin Zhang, Jinhao Hu, Jinweng Tao, Yuanbing Wang, Huajun Sun, Ali Shoaib, Jing-Feng Li, Bo-Ping Zhang (Journal of Advanced Ceramics, 2026)
Abstract BiFeO3–BaTiO3 ceramics have been shown to possess considerable promise in the domain of high-temperature lead-free piezoelectric applications, a property attributable to their elevated Curie temperature and superior piezoelectric properties. However, the inherent issue of high leakage current within this system is a consequence of the unavoidable formation of secondary phases within thermodynamically unstable temperature ranges and the volatility of Bi. This issue severely compromises the high-temperature polarization stability and piezoelectric performance. This high conductance hinders the enhancement of the overall performance and obscures the evolution patterns of intrinsic defects and their influence mechanisms on macroscopic properties, necessitating in-depth investigation. The present study successfully prepared a series of BiFe1+xO3–BaTiO3 ceramics using a one-step sintering process. The Fe content was deliberately designed t o exhibit both severe excess and deficiency states. It was found that the Fe non-stoichiometry-induced unique defect evolution behavior. A detailed investigation was conducted to ascertain the influence of the defect configuration on the electrical insulation properties across a range of temperatures and strain levels. The respective contributions of the defect-dipoleand space-charge-induced built-in electric fields to the strain response (before and after polarization) were also examined. It is noteworthy that the pure 0.7BiFeO3–0.3BaTiO3 system exhibits remarkable comprehensive properties at room temperature (piezoelectric constant d33* = 1021 pm/V, strain S ≈ 0.38%, and piezoelectric coefficient d33 = 201 pC/N). The material exhibits a high Curie temperature of approximately 501 °C, accompanied by a notable high-temperature piezoelectric activity. The peak d33 and d33* values are approximately 380 pC/N (measured at 317.9 °C) and 1481 pm/V (measured at 125 °C), respectively.

Lead‐Free Hybrid Halide Perovskite for Piezoelectric Energy Harvesting - Prabhanjan Pradhan, Swadesh Paul, Ranjit Kumar Pradhan, Anuja Datta, Biplab K. Patra (Small, 2026)
ABSTRACT Halide perovskites are widely recognized for their exceptional optoelectronic properties, cost‐effective fabrication, and tunable chemical compositions, which make them highly versatile in photovoltaics, LEDs, and mechanical energy harvesting. Here we have developed a novel manganese‐based lead‐free Benzyl trimethyl ammonium manganese bromide (BTMB) perovskite in the polar non‐centro symmetric space group P2 1 system, which shows strong piezoresponse properties measured using sophisticated Piezo Force Microscopy (PFM) and Switching Spectroscopy Piezo Force Microscopy (SS‐PFM). BTMB exhibits a direct bandgap of 4.3 eV along with a bright luminescence in the visible region due to ligand‐to‐metal charge transfer mechanism. The material demonstrates a polarization saturation value of 4.0 µC/cm 2 with d 33 value of 3.95 pC/N measured using quasi electrostati c d 33 meter on a pellet of thickness 1.5 mm. PFM results show notable ±180 0 phase changes upon application of bias with characteristic butterfly and hysteresis loop, a clear indication of reversal of polarization switching. Further, we have fabricated a mechanical energy‐harvesting device by incorporating BTMB into polydimethylsiloxane (PDMS) polymer matrix containing 30 weight percent of the material to achieve a peak output voltage of 1.1 V and a peak current density of 250 nA/cm 2 with an achievable output power of ∼1.1 µW/cm 2 at RT.

A bismuth ferrite-based lead-free piezoelectric ceramic surpassing PZT-8 in thermal stability - Xiaodong Yan, Chaoyang Shi, Jianjun Wu, Kevin Chen, Zhengbao Yang (Journal of Materials Chemistry A, 2026)
This work develops a defect-engineered bismuth ferrite-based lead-free ceramic, achieving industry-leading temperature stability surpassing PZT-8 for high-temperature electronics.

Functionally graded lead-free piezoelectric composites for enhanced ultrasound energy harvesting - Haoyun Ma, Xing Huang, Ruijun Qian, Donglai Tang, Xiang Lv, Laiming Jiang, Jiagang Wu (Journal of Materials Chemistry A, 2026)
Potassium Sodium Niobate (KNN)-based lead-free piezoelectric ceramics have emerged as a promising candidate for next-generation ultrasonic electronics, owing to their biocompatibility and exceptional piezoelectric properties. However, conventional dense KNN ceramics...

Ultrahigh electromechanical response at low electric field in Pb-free piezoelectric ceramic via defect engineering - Zilin Cao, Hongbo Liu, Minghao Liu, Hengchang Nie, Zhen Liu, Genshui Wang (Acta Materialia, 2026)

Effect of heterogeneous and homogeneous reactive templates on microstructures and piezoelectric properties of [001]-textured PMN-28PT piezoelectric ceramics - Yulong Zhang, Mingyang Tang, Xin Liu, Yike Wang, Zhuo Xu, Yongke Yan (Journal of the European Ceramic Society, 2026)

(K,Na)NbO3-based lead-free ceramic/polyvinylidene fluoride piezoelectric composite for biomimetic wound healing via endogenous electric field simulation - Linfeng Fan, Zhiyuan Dai, Xinna Bai, Xudan Liu, Zhangui Tang, Hao Pan, Yan Zhang, Dou Zhang (Biomaterials Advances, 2026)

KNN-based lead-free piezoelectric ceramics with high kp and d33 through synergistic enhancement strategies - Weixu Meng, Dongping Li, Wenlong Yang, Yu Wang, Jianping Yu, Ziteng Liu, Zhicheng Qin (Ceramics International, 2026)

Lead-free BCZT ceramics enable high energy harvesting through critical grain size optimization - Na Lin, Jinfeng Lin, Yali Hao, Anming She, Yongqi Wei, Cheng Shi, Wu Yao (Ceramics International, 2026)

Synergistic IL grafting and NH2-ZIF-8 doping enable PVDF composite membranes with enhanced separation, antifouling, and piezo-photocatalytic degradation functions - Xiaonan Hao, Ying Xue, Yue Wu, Shulin Sun (Journal of Environmental Chemical Engineering, 2026)

Degradation of water contaminants by barium titanate (BaTiO3)-based materials: A critical review - Sahil Rana, Akshay Verma, Pooja Dhiman, Ackmez Mudhoo, Gaurav Sharma (Journal of Water Process Engineering, 2026)

Advances in Soft Solid State Electrocaloric Refrigeration - Shumao Xu, Xiujun Fan, Songyue Chen, Jeong Min Baik, Jun Chen (Advanced Functional Materials, 2026)
Abstract Electrocaloric cooling has emerged as a promising solid‐state substitute for traditional vapor‐compression refrigeration, driven by the need for environmentally friendly and energy‐efficient technologies. This review hightlights recent advances in ceramic ferroelectrics in multilayer ceramic capacitors (MLCCs) and polyvinylidene fluoride (PVDF) copolymers‐based efficient, self‐oscillating soft refrigeration systems. The introduction of lead‐free ceramic ferroelectrics in MLCCs has significantly enhanced the performance and durability of electrocaloric cooling systems, making them energy‐efficient and capable of withstanding extensive operational cycles. Simultaneously, ternary copolymers, P(VDF‐TrFE‐CFE) and P(VDF‐TrFE‐CTFE) along with their composites and modified derivatives have demonstrated superior promise due to their enhanced polarization‐field coupling and fatigue resistance compared to irradiated copolymers. These systems leverage thei r high thermal conductivity and substantial electrocaloric responses to facilitate rapid heat dissipation without external mechanical components, enabling efficient electronic thermal management. The synergy between electro‐thermomechanical properties has paved the way for these solid‐state cooling technologies to potentially replace conventional systems, reducing energy consumption and eliminating the use of harmful refrigerants. This review underscores the pivotal role of molecular and interface engineering in eco‐friendly electrocaloric cooling solutions, focusing on enhancing cooling efficiency through optimized thermal load management, strategic dipole alignment to improve polarization‐field interaction, and the development of ceramic multilayer capacitors and irradiated P(VDF‐TrFE) with large adiabatic temperature changes and high energy densities, promising electronic thermal management and on‐chip cooling in advanced computing and telecommunications.

Electrocaloric Cooling‐Driven Self‐Cooling Dielectrics: Integrated Energy Storage and Refrigeration for High‐Power Capacitors - Da Zu, Zhanpeng Zhang, Dongliang Shan, Wenjun Cao, Yunya Liu (Advanced Functional Materials, 2026)
Abstract The thermal failure bottleneck in high‐power polymer capacitors severely limits their energy storage performance breakthroughs. Composite materials combining excellent thermal management capabilities with high energy storage density represent an effective solution to this problem. This study proposes an integrated energy storage‐thermal management design strategy: using a relaxor ferroelectric polymer P(VDF‐TrFE‐CFE) as the matrix and incorporating Ba 0.6 Sr 0.4 TiO 3 (BST) nanoparticles with varying weight fractions (0–23.08 wt.%) to construct high‐performance polymer‐based nanocomposites. By synergistically regulating the interfacial polarization effect and polarization entropy change, dual breakthroughs in electrocaloric (EC) cooling and energy storage performance are achieved. This study employs infrared thermal imaging technology to directly measure the EC response of composit e films. Experimental results show that when the BST weight fraction is 16.67 wt.%, the composite achieves optimal overall performance: under an electric field of 110 MV m −1 , the recoverable energy density W rec reaches 4.26 J cm −3 , which is a 20.34% improvement over the pure polymer, with the η of 70.17%; under an electric field of 100 MV m −1 , the EC temperature change reaches 5 °C, representing a 32.63% enhancement compared to the pure polymer. Therefore, this work achieves a synergistic enhancement of dielectric energy storage and EC cooling performance within a single material system.

Hierarchal structures tuned electrocaloric and electromechanical performance in PVDF-based tetrapolymers - Guanchun Rui, Wenyi Zhu, Qin Zou, Li Li, Siyu Wu, Ruipeng Li, Raymond Khayat, Mark A. Aubart, Thierry Lannuzel, Fabrice Domingues Dos Santos, Lei Zhu, Q. M. Zhang (npj Flexible Electronics, 2026)

Three-mode phase change, radiative cooling, and piezoelectricity integrated PVDF/SiO2@n-octadecane microcapsule/PVDF-HFP films for all-weather thermal management - Qinkun Zhang, Yong Deng, Hongen Nian, Run Huang (Applied Thermal Engineering, 2026)

Preparation and performance study of hydrophobic radiative cooling coatings based on PVDF/Al2O3/SiO2 - Wen Su, Jing He, Xiaotong Lin, Zhixuan Liang, Changhong Wang (Solar Energy Materials and Solar Cells, 2026)

Electrocaloric cooling efficiency: Comparative insights on P(VDF-TrFE-CFE) polymer and BSTM ceramics - Sukhendu Sadhukhan, Nouh Zeggai, Brahim Dkhil, Sakyo Hirose, Martino Lobue, Morgan Almanza (Ceramics International, 2026)

Synergistic Sono-Enhanced Photocatalytic Degradation of Antibiotics: Unlocking the Potential of Heterojunctions and Piezoactive Composite Membranes - Samar Ben Atig, Bruna F. Gonçalves, Moufida Chaari, Samia Dhahri, Hugo Salazar, F. Jomni, S. Lanceros‐Méndez (Polymers, 2026)
The remediation of contaminants of emerging concern (CECs) requires innovative, high-efficiency, and sustainable technologies. Here, we investigate active polymeric membranes incorporating TiO2/ZnO heterojunctions for synergistic sono-enhanced photocatalytic water treatment under both UV and visible-light irradiation. TiO2/ZnO composites were synthesized and characterized, confirming the formation of type II heterojunctions with tailored optical properties for sunlight-driven photocatalysis. The catalysts were integrated into poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) and poly(vinylidene fluoride-co-trifluoroethylene) (PVDF-TrFE) matrixes using electrospinning (ES) and thermally induced phase separation (TIPS). ES membranes, specifically the ZnO-rich heterojunction within a PVDF-TrFE matrix (3T-7Z@TrFE ES), achieved the highest performance toward ciprofloxacin (CIP) degradation, reaching 71 and 57% under UV and visible light, respectively. The hybridization of the meth od by coupling ultrasound induced significant synergistic effects, with relative enhancement factors up to 1.38. Furthermore, the sono-enhanced photocatalytic pathway shifted the degradation mechanism towards the early fragmentation of the harmful piperazine ring, yielding a more sustainable degradation process. In addition, the composite membranes showed selective antibacterial activity against S. aureus, making this a multifunctional platform able not only to degrade CECs but also to mitigate membrane fouling. Overall, this work demonstrates the potential of tailored heterojunctions and composite membranes as sustainable platforms for the remediation of recalcitrant CECs in water, highlighting the synergy between photoactivity, piezoelectricity, and mechanistic control.

Antifouling Oil–Water Separation Membrane: Achieving Efficient Demulsification and Surface Oil Contamination Removal through Enhanced Piezoelectric Properties - Bocheng Xiang, Yuxuan He, Zhiguang Guo (ACS Applied Materials & Interfaces, 2026)
Stable oil–water emulsions containing micron-sized oil droplets readily foul conventional separation membranes, leading to severe pore blockage, rapid flux decline, and reduced operational stability. In this work, a piezoelectric nanofibrous membrane based on polarized PVDF/BaTiO 3 composite fibers was developed for enhanced emulsion separation and antifouling performance. The incorporation of tetragonal BaTiO 3 nanoparticles promoted β-phase formation in PVDF and improved the piezoelectric response of the membrane after polarization treatment. Compared with nonpolarized membranes, the polarized membrane exhibited improved flux stability and oil rejection performance during continuous oil–water emulsion separation. The enhanced separation behavior is correlated with the piezoelectric-assisted interfacial response generated during membrane operation. Under mechanical perturbation induced by fluid flow, localized piezoelectric polarization may contribute to reducing oil adhesion and supp ressing fouling accumulation on the membrane surface. Although the precise interfacial mechanism requires further direct experimental verification, the observed improvement in antifouling behavior is consistent with previously reported piezoelectric interfacial effects. The optimized membrane achieved a separation efficiency above 99% together with stable long-term flux performance during continuous emulsion separation. This work demonstrates a feasible strategy for integrating piezoelectric functionality into nanofibrous membranes for antifouling oil–water separation.

Design and realization of high performance textured lead-free piezoelectric ceramics through human-AI collaboration - Aman Nanda, Debjyoti Bhattacharya, Nayeon Kang, Shankar Kunwar, Shashank Priya, Jungho Ryu, Wesley F. Reinhart, Michael Lanagan (Nature Communications, 2026)
Developing multielement doped Pb-free (K,Na)NbO₃ piezoelectrics often hindered by complex doping trends and tedious trial-and-error experimentation. Here, we present a human-in-the-loop, artificial intelligence guided materials design framework that utilizes large language models to capture implicit structure-property knowledge from prior literatures and propose new compositions. Expert intervention further directs experimental realization based on materials science principles and experiential knowledge, accelerating discovery of targeted compositions. Using collaborative strategy, synthesized random composition exhibiting piezoelectric charge constant d33 of 440 − 500 pC/N which further enhanced to 600-620 pC/N through crystallographic texturing and sintering aid optimization. Despite inherently off-MPB degradation (at R.T), this composition maintained steady electromechanical coupling (kij) and d31 up to 160 oC. To validate practical relevance, a cantilever-based magneto-mechano-elec tric (MME) energy harvester was fabricated, delivering a power density of ~ 705μW/cm3 at the second harmonic, outperforming reported Pb-free MME designs. Here, we demonstrate an exceptional approach towards developing application-specific functional materials through the synergy of AI-driven recommender systems, human expert validation, and experimental realization. The authors demonstrate artificial intelligence guided human-in-the-loop strategy to design high-performance Pb-free piezoelectric ceramics, achieving strong thermal stability and enhanced energy-harvesting performance for next generation functional devices.

Embedding microcrystalline SnSe into polyvinylidene fluoride foam: A novel piezoelectric composite for pollutants degradation - Yue Liu, Huanyan Xu, Bo Li, B B Wang, Lu Zhang (Journal of Alloys and Compounds, 2026)

Freestanding ferroelectric membranes via ionic unlocking van der Waals interface - Ying Liu, Xi Zhang, Zhang Zhang, S H Wang, Yi-Xiang Wang, Lisha Liu, Yaojin Wang, Yixin Yang (Nature Communications, 2026)
Freestanding oxide films have attracted significant interest for their potential applications in flexible electronics. However, the common use of sacrificial layers hinders the development of freestanding oxide films that meet industrial demands for larger area, device-scalable thickness and low cost. Here, we present a water-assisted ionic unlocking strategy that enables the rapid exfoliation of centimeter-scale, freestanding ferroelectric Pb(Zr,Ti)O3 membranes from Pb(Zr,Ti)O3/Pt/Mica. Leveraging density functional theory and ab initio molecular dynamics simulations, we identify water-induced potassium ion leaching from the Mica substrate as a key interfacial weakening pathway that substantially reduces the Pt/Mica interfacial binding energy, thereby enabling crack propagation driven by capillary forces along the weakened interface. The resulting 1×1 cm2 Pb(Zr,Ti)O3 membranes demonstrate a remarkable piezoelectric coefficient of 528 pC N−1, approximately twice that of their clamped c ounterparts on Mica. Moreover, by incorporating these membranes, we fabricate self-powered flexible acoustic sensors for high-fidelity sound recording and speech recognition, achieving a speech recognition accuracy exceeding 93%. This work represents a significant advance in both the scalable fabrication of freestanding ferroelectric membranes and the engineering of high-performance flexible sensors. The authors propose a water-assisted ionic-unlocking strategy to fabricate ferroelectric membranes for self-powered flexible acoustic sensors. They identify water-induced potassium ion leaching from the Mica substrate as an important interfacial weakening pathway.

A P(VDF-TrFE)/AlN nanocomposite with high filler content: Towards a “hard ferroelectric soft material” with enhanced properties for additive printing - Wolfgang Hilber, Sebastian Lang, Bernhard Jakoby (Micro and Nano Engineering, 2026)
In recent work, we have successfully employed Poly (vinylidene fluoride-trifluoroethylene) [P(VDF-TrFE)] as an additively printed functional layer embedded in organic coatings on metallic substrates for various piezoand pyroelectric sensing applications. In practice, however, printed functional layers typically exhibit less favorable physical properties compared to their ideal bulk values. Here, we present a strategy to enhance the ferroelectric performance of a printable composite formulation by incorporating ceramic aluminum nitride (AlN) nanoparticles at high fraction into the hosting P(VDF-TrFE) matrix. Although AlN exhibits comparatively modest piezoelectric properties on its own, its inclusion yields a composite whose effectively usable polarization substantially exceeds that of the baseline P(VDF-TrFE) formulation used so far. By analogy to “hard-magnetic soft materials” (soft polymers with hard magnetic fillers), the resulting nanocomposite may be viewed as a “hard ferroelectri c soft material” that combines mechanical compliance and ease of processing with significantly improved ferroelectric functionality for additive manufacturing.

High-Performance Piezoelectric Nanogenerators based on BNBTMn/P(VDF-TrFE) Nanocomposites for Wearable Voice and Motion Sensing - Jianhao Du, Yilin He, Yuansen Qiao, Jun Liang, H P Wang, Y W Sun, Yihan Yan, Jin Zhang (Journal of Alloys and Compounds, 2026)
The development of efficient and sustainable energy harvesting devices for miniaturized electronic devices has become increasingly significant in the industry 5.0 era. Among various potential materials, piezoelectric polymer-ceramic composites have emerged as a promising candidate for piezoelectric nanogenerators (PENGs) exploiting the synergistic effect of the high piezoelectric response of ceramic fillers and the flexibility and processing advantages of the polymer matrix. In this work, environmentally friendly PENGs based on Mn-doped (Bi 0.5 Na 0.5 )TiO 3 -BaTiO 3 (BNBTMn)/P(VDF-TrFE) microcomposites with different mass ratios of the ceramic inclusions were prepared using a facile solution casting route. These PENGs demonstrate simultaneously large output power, excellent sensitivity, and decent cyclability under various mechanical stimuli. In particular, the 3 wt% BNBTMn-loaded PENGs exhibit an output voltage of 52 V, a peak-to-peak short-circuit current of 12.8 µA, and an output p ower density of 25.9 μW/cm 2 under a cyclic impact load of 175 N at 5 Hz, outperforming almost all the piezoelectric microcomposites employing lead-free piezoelectric ceramic inclusions to date. The enhanced performance is attributed to improved interfacial polarization and local electric field concentration arising from the optimized dispersion of BNBTMn fillers within the polymer matrix. The output remains nearly unchanged after 15000 operating cycles of continuous impacts, suggesting excellent durability of our PENG. More intriguingly, the (BNBTMn)/P(VDF-TrFE) microcomposite-based PENG can capture the subtle movement of Adam’s apple (i.e. laryngeal prominence), unambiguously underpinning the viability of integrating them into wearable electronics as highly sensitive contact-mode throat vibration and motion sensors.

Piezoelectric scaffolds for bone regeneration: a systematic review of preclinical studies - Marco Minelli, Simone Micalizzi, Vincenzo Longobardi, Elizaveta Kon, Paolo Oliva, Federico Della Rocca (Frontiers in Bioengineering and Biotechnology, 2026)
Introduction Critical-sized bone defects remain a major challenge and often require reconstruction grafts. Conventional scaffolds don’t reproduce the dynamic electromechanical behavior of native bone. Piezoelectric scaffolds have emerged as a promising strategy to overcome these limitations by converting mechanical stimuli into bioactive electrical signals capable of enhancing osteogenesis. Methods A systematic review was conducted in accordance with the PRISMA 2020 guidelines and registered in PROSPERO (ID: 1359740). A comprehensive search of PubMed/MEDLINE, Scopus, Embase, and Cochrane Central Register of Controlled Trials was performed. In vivo animal and clinical studies evaluating piezoelectric scaffolds for bone defect repair were included. Data extraction and risk of bias assessment were performed independently by two reviewers. Outcomes of interest included micro-computed tomography (micro-CT), histological findings, and biomechanical properties. Results Ten preclinical in vivo studies (2020–2025) were included. No eligible human clinical studies were identified. The included studies involved mainly rodent models, with some studies in rabbits and sheep. Most studies investigated critical-sized calvarial defects, while others evaluated load-bearing models. Piezoelectric scaffolds—primarily based on PVDF, PVDF-TrFE, and BaTiO 3 composites—consistently demonstrated improved bone regeneration compared with conventional scaffolds. Micro-CT analysis showed higher bone volume fraction (BV/TV) and bone mineral density (BMD) across studies, with BV/TV values reaching approximately 35%–36% at 8 weeks in several models. Histological analyses confirmed enhanced new bone formation, improved tissue organization, and better scaffold–bone integration, often with reduced fibrous tissue formation. Additive manufacturing techniques enabled precise control of scaffold architecture and were widely used, while external mechanical stimulation further enhanced osteogenic outcomes i n some studies. Conclusion Piezoelectric scaffolds represent a promising approach for bone regeneration, demonstrating superior regenerative performance compared with conventional scaffolds in preclinical models. Their ability to generate bioactive electrical signals, combined with advanced fabrication techniques, supports their potential for clinical translation. However, current evidence is limited to preclinical studies with heterogeneous methodologies. Further standardized studies and clinical investigations are needed to confirm their safety, efficacy, and long-term performance.

A Composite Layered Piezoelectric Pressure Sensor for Dynamic Monitoring with Enhanced Sensitivity and Temperature Adaptability - S S Liu, Dazhao Zhou, Jinghua Lin, Jifang Tao (Sensors, 2026)
Piezoelectric pressure sensors for dynamic monitoring face a trade-off between charge output and measurement range, and existing high-sensitivity designs are largely confined to narrow ranges. This study presents a composite layered piezoelectric pressure sensor in which a 316L stainless-steel diaphragm drives a centrally suspended PZT-5H wafer supported by a perforated alumina gasket, with the wafer thickness and cavity radius optimized under a 10 MPa full-scale stress constraint. Over 0–10 MPa, quasi-static calibration gave a highly repeatable quadratic pressure–charge relationship (R2=0.99995) with a maximum residual below 1% FS. The sensitivity is pressure-dependent: the secant sensitivity increased monotonically from 3.16 pC/kPa at 1 MPa to 5.36 pC/kPa at 10 MPa, reflecting a stress-stiffening response rather than a measurement tolerance band. The output deviation remained within 3% from 25 °C to 150 °C. Shock-tube testing yielded a resonance of ∼50 kHz and a mutually consistent 1 0–90% leading-edge interval of 10.12 μs. Combining high charge sensitivity over a wide 0–10 MPa range with a fast transient response and stable operation up to 150 °C, the proposed sensor is suited to dynamic pressure-pulsation monitoring in fluid-power and thermal and power-plant fluid systems.

Carbon based functional materials enable multifunctional flexible strain sensors for wearable and implantable applications - Siqi Wang, Xuemeng Li, Enci Xie, Shuo Gao (Discover Nano, 2026)
Flexible strain sensors are essential components for wearable electronics, implantable biointerfaces, and soft human-machine systems. As application scenarios expand from epidermal monitoring toward long-term in vivo operation, increasingly stringent requirements are imposed on multifunctionality, mechanical compliance, signal stability, and biointegration. Carbon-based functional materials, owing to their tunable electrical properties, structural versatility, and favorable electromechanical compatibility, have emerged as a central materials platform for next-generation flexible strain sensors. This review presents a comprehensive, mechanism-oriented overview of carbon-enabled flexible strain sensing, encompassing piezoresistive, capacitive, and piezoelectric transduction modes. This review systematically examine how carbon material dimensionality including low-dimensional nanofillers, two-dimensional sheets, and three-dimensional porous, governing sensitivity, durability, and long-ter m device reliability. Particular emphasis is placed on contrasting the fundamentally different design requirements of wearable and implantable systems, including sensitivity-stability trade-offs, tissue-level mechanical matching, and operational robustness in complex biological environments. Distinct from prior materialor device-centric reviews, this review establishes a unified framework linking carbon architectures, sensing mechanisms, and application contexts, thereby clarifying critical bottlenecks and design principles for advancing multifunctional, biointegrated strain sensors toward practical and translational use.

Patterned PVDF/ZnO-MXene piezoelectric energy harvester driven by bee wing-surface deformation - Zhiyun Ma, Yuxia Li, Yu Zhang, Mengdan Yan, W X Wang, Yan S, Xi Zhang, Jieliang Zhao (npj Flexible Electronics, 2026)
Cyborg insects have shown considerable potential in disaster rescue, environmental monitoring, and hazardous-area exploration, but the power supply of their onboard electrical stimulation systems remains limited by the large mass and short service life of conventional chemical batteries. In this study, we propose a patterned flexible piezoelectric energy harvesting strategy based on bee wing-surface deformation and design a patterned piezoelectric deformation energy harvester (PDEH) capable of conformal integration with the wing surface through kinematic analysis and morphological characterization of bee wings. In addition, a PVDF/ZnO-MXene nanocomposite piezoelectric film with high β -phase content, improved electrical conductivity, and enhanced femtosecond-laser processability was fabricated. The results show that the optimized nanocomposite film delivers an approximately 120% increase in the d 33 coefficient compared with pure PVDF and exhibits superior laser processability. In outp ut tests of the PDEH integrated with bee wings, the fabricated device generated stable outputs of approximately 1.2 V and 186 nA, with a power density of up to 166 μW g −1 , surpassing most of the previously reported insect mechanical energy harvesters. This study provides a new design strategy for insect mechanical energy harvesting and may contribute to the development of auxiliary power modules for future cyborg insect systems.

High‐Performance Weavable Piezoelectret Fibers via Scalable In Situ Poling Melt‐Spinning for Real‐Time Knee Joint Rehabilitation Monitoring - Huanhuan Zhang, Tong Li, M T Liu, Senhao Zhang, Q Chen, Jinping Qu, Zi Wang (Advanced Materials, 2026)
ABSTRACT The scalable production of high‐performance piezoelectric fibers remains a major hurdle for smart textile applications. Here, we report an in situ polarization strategy integrated into an industrially viable melt‐spinning process for the continuous fabrication of piezoelectric polypropylene/barium titanate (PP/BTO) composite fibers. This approach simultaneously induces interfacial cavitation to form electret pore structures and accomplishes rapid dipole polarization under a high electric field during fiber drawing, eliminating the need for post‐processing. The optimized PP/BTO fibers exhibit a high piezoelectric coefficient ( d 33 ) of 1.8 pC/N and a surface potential of −3.4 V, achieved with an ultralow poling time of 0.3 s. The fibers demonstrate exceptional flexibility and weavability, enabling their integration into large‐scale textiles. As a proof‐of‐concept, a sensor‐woven insole is constructed for real‐time gait monitoring. Combined with machine learning, the system suc cessfully recognizes different gait patterns with over 84% accuracy, showcasing significant potential for personalized rehabilitation diagnostics. This work provides an efficient and scalable pathway for manufacturing functional fibers, bridging the gap between laboratory innovation and industrial production.

Interfacial charge modulation in Ba0.85Ca0.15Zr0.1Ti0.9O3 /graphene dual-filler reinforced polyvinylidene fluoride nanocomposites for improved piezoelectric energy harvesting - Neha Thakur, Prakash Gopalan, Jayant Kolte (Ceramics International, 2026)

A ground-up life-cycle sustainability framework for integrating triboelectric Nanogenerators into transportation-energy systems - Yafeng Pang, Xi Zhu, Hongwei Lin, Feng Li (Cleaner Materials, 2026)
The sustainable development of transportation-energy systems increasingly relies on traffic monitoring and dissipated mechanical energy harvesting technologies. Triboelectric nanogenerator (TENG) enhanced pavements offer such potential, but their life cycle implications remain insufficiently understood. In particular, it is unclear whether integrating TENGs into pavement structures reduces or increases overall life cycle cost, energy use and carbon emissions once material production, construction and long-term operation are considered. This study addresses this gap by conducting a cradle to grave assessment of the environmental and economic impacts associated with embedding vehicle-side TENGs (V-TENGs) and road-side TENGs (R-TENGs) into transportation-energy systems. Four pavement configurations, including conventional asphalt pavement without V-TENG, tribo-inspired smart pavement without V-TENG, asphalt pavement with V-TENG and tribo-inspired smart pavement with V-TENG, are evaluated using energy payback period, Levelized Cost of Energy (LCOE), environmental profile and sensitivity analysis across human health, resource depletion and ecosystem quality. Results show that TENG integration effectively captures wasted mechanical energy and contributes to lower life cycle energy consumption and carbon emissions while maintaining a balanced overall environmental burden. These findings provide quantitative evidence for the sustainability benefits of TENG enabled smart pavements and offer practical guidance for their future large-scale deployment within transportation infrastructure.

Interface‐Engineered PVDF / BaTiO 3 Composite Nanofibers With Amino‐Terminated Liquid Butadiene Rubber for Flexible Piezoelectric Energy Harvesting - Chunjin Ai, Wei Zhang, Yucheng Pan (Journal of Applied Polymer Science, 2026)
ABSTRACT Self‐powered flexible piezoelectric devices based on polyvinylidene fluoride (PVDF) face a critical trade‐off between piezoelectric output and mechanical flexibility. In this study, an amine‐terminated liquid butadiene rubber (ATPB) toughened PVDF/BaTiO 3 (BTO) flexible nanofiber membrane is fabricated via electrospinning to achieve an optimized balance between piezoelectric output and mechanical durability. The ATPB coating serves as a low‐modulus elastomeric interphase on BTO nanoparticles, mitigating the modulus mismatch and suppressing interfacial stress concentration while maintaining high ductility, with elongation at break exceeding 33%. Through the combined effects of chemical hydrogen bonding from ATPB and heterogeneous nucleation of BTO, the relative content of polar β‐phase reaches 62.4% (Lambert–Beer law) and 60.1% (multi‐peak intensity ratio method), with a β‐phase absolute crystallinity of 33.38%. The assembled piezoelectric nanogenerator (PENG) produces a stable open‐circuit voltage of 10–15 V, representing an approximately 2–3 fold enhancement over pure PVDF devices. The short‐circuit current reaches 7 μA, with a peak power density of ~4 μW cm −2 , and the device retains ~92.3% output after 5000 cycles. This research provides an effective strategy for developing flexible PVDF‐based materials for energy harvesting and wearable sensors.

Study of Dielectric and Piezoelectric Properties of Reduced Graphene Oxide‐Reinforced Poly (Vinylidene Fluoride‐Co‐Hexafluoropropylene) Based Three Phase Composite Films for Energy Storage and Harvesting Applications - S. Parthasarathy, S. Behera, Srikanta Moharana, Harshavardhan Chouhan (Energy Storage, 2026)
ABSTRACT Recently, polymer‐based composites have attracted significant attention for capacitive energy storage and harvesting due to their excellent mechanical flexibility and dielectric performance. Solution casting has been employed to produce flexible and lightweight PVDF‐HFP films incorporating 10 wt% of Li 3 Mg 4 NbO 8 ceramic and nanosheets of reduced graphene oxide (rGO) at varying concentrations. To determine and calculate the fraction of β phase, X‐ray diffraction (XRD) and Fourier transform infrared spectra were examined. The fraction of β phase is found to be greater than 50% in every composite film sample. The dielectric constant of the composite films rises as the rGO concentration is increased up to 8 wt%, after which it decreases. The static hysteresis loops with 8% of rGO loading yield the greatest energy storage efficiency of 93.7%. Measurements of the piezoelectric charge and voltage coefficients showed values as high as “−33 pCN −1 ” and “0.3 mVN −1 ,” respectively. Increasing the rGO content improves the composites' UV–visible absorbance, which makes them useful for light shielding. The 8 wt% rGO piezoelectric harvester is a good option for piezoelectric energy harvesting applications since it generates the maximum open‐circuit voltage of approximately 4 V with easy hand tapping.

Distinguishing Nanoscale Electromechanical Properties in Hybrid Ferroelectric Systems: Insights from Bismuth Ferrite and PVDF-TrFE Flexible Nanocomposites - Pierre Nickmilder, Sergio González Casal, Philippe Leclère (ACS Omega, 2026)
peer reviewed

Recent Advances in AI and Signal Processing for PZT-Based Structural Health Monitoring - Reza Soleimanpour (Infrastructures, 2026)
Structural health monitoring (SHM) systems fundamentally rely on effective sensing technologies for reliable damage detection and structural condition assessment. Among the available sensing approaches, piezoelectric (PZT)-based transducers are widely used in civil engineering due to their dual actuation–sensing capability, high sensitivity, low cost, and suitability for real-time monitoring. However, SHM performance not only depends on the sensing hardware, but also on the signal processing techniques that extract meaningful damage-related information from measured responses. Recently, Artificial Intelligence (AI), particularly machine learning (ML) and deep learning (DL), has shown strong potential to enhance automation and improve the performance of SHM systems. This paper provides a critical review of signal processing and data-driven learning approaches for PZT-based guided-wave (GW) SHM and nondestructive testing (NDT), with applications to metallic, composite, and concrete struc tures. The review covers developments from early ML-based GW SHM methods to recent advances in DL, hybrid frameworks, and physics-informed approaches. Although emphasis is placed on civil infrastructure, developments in other fields such as aerospace and energy engineering are also reviewed due to their role in validating GW-based SHM methodologies. The fundamental theory of PZT sensing and guided wave propagation is introduced to establish the required background for monitoring techniques. Classical signal processing methods are then reviewed, followed by AI-based SHM frameworks, with particular emphasis on hybrid approaches that integrate physics-based signal processing with data-driven models to improve robustness, accuracy, and generalization. Key challenges such as environmental variability, sensor degradation, limited labeled data, and model transferability are discussed, along with future research directions including physics-informed machine learning (PIML), transfer learning, explainable AI, and baseline-free SHM. The review highlights that hybrid and physics-informed frameworks offer strong potential for field deployment by improving robustness, reducing data dependency, and enhancing generalization capability. A key contribution of this work is the comparative synthesis of signal processing, ML, DL, and hybrid methodologies across different material systems and structural types, together with a structured discussion of the challenges and future research directions for real-world implementation.

Smart Prediction of Piezoelectric Response in PVDF/h-BN Composites: Combining Materials Science and Machine Learning - Mahesh Pratap Gotte, P.S. Rama Sreekanth (Arabian Journal for Science and Engineering, 2026)

Observation of giant acoustoelectric currents in graphene on lead magnesium niobate–lead titanate - Hamed Atashbar, Hakhamanesh Mansoorzare, Tara Jabegu, Sidong Lei, Mary E. Galanko Klemash, Sarah S. Bedair, Reza Abdolvand (Nature Communications, 2026)
Abstract Acoustoelectric (AE) devices enable coupling between acoustic waves and mobile charge carriers, offering a route toward RF-to-DC conversion, RF power sensing, energy harvesting, and responsive sensing applications. The efficiency of this coupling depends on both the electromechanical properties of the piezoelectric substrate and the transport properties of the conductive film interacting with the surface acoustic wave (SAW). Here an AE SAW delay line platform is presented for generating large AE currents using graphene on lead magnesium niobate–lead titanate (PMN–PT). Leveraging graphene’s high carrier mobility and the strong electromechanical coupling of (111)-cut PMN–PT, this platform achieves giant AE current generation. Additionally, AE responsivity ( $${{\boldsymbol{{\mathscr{R}}}}}_{{{\bf{AE}}}}$$ R AE ) is introduced here as a figure of merit for comparing AE platforms. The platform comprises interdigitated transducers (IDTs) deposited and patterned on the bulk PMN–PT surface for launching SAW and a monolayer graphene film positioned within the SAW propagation region. Experimental measurements confirm generation of AE current and voltage within the SAW passband, with the AE current reaching up to 90.39 µA at an RF input power of 20 dBm, corresponding to an $${{\boldsymbol{{\mathscr{R}}}}}_{{{\bf{AE}}}}$$ R AE of 7.66 µA/(W·MHz). The reported AE current and AE responsivity outperform most of the previously reported platforms, validating the effectiveness of the proposed approach.

Ultra-wide and Linear Range Flexible Piezoelectric Sensor Based on PVDF/BNNS Composites - Yingbo Guan, Yingjie Li, Houyu Zhang, Haiyun Yang, Hongning Ye, Xueren Chen, Mengjie Jiang, Mengyong Lei (Journal of Advanced Dielectrics, 2026)
Flexible piezoelectric sensors have attracted significant attention in the field of structural health monitoring (SHM) owing to their excellent frequency response capability and conformal attachment to complex surfaces. However, the conventional blending methods often fail to achieve uniform dispersion and ordered orientation of nanofillers within polymer matrices, which limits the sensitivity and linear measurement range. To address this issue, a fabrication strategy for flexible piezoelectric sensors based on the induced orientation by shear flow-is proposed. During the blade coating process, a strong shear flow field is generated, which induces high-modulus two-dimensional boron nitride nanosheets (BNNSs) to form a highly ordered parallel lamellar structure within the polyvinylidene fluoride (PVDF) matrix. This architecture not only constructs an efficient stress transfer pathway, but also significantly enhances the deformation resistance and structural stability of the composite. T he fabricated PVDF/BNNS composite piezoelectric sensor achieves an ultra-wide linear measurement of 0-619 MPa, approximately 1.6 times that of pristine PVDF, while maintaining a high voltage sensitivity of 16.6 mV MPa -1 , which is about 2.3 times higher than that of pure PVDF based sensor. Furthermore, the sensor exhibits excellent response capability for broadband vibration signals in the frequency range of 20-100 Hz, meaning its practical potential for intelligent monitoring and condition sensing of industrial equipment.

Flexible piezoelectric sensor based on WO₃@UiO-66-NH₂ heterojunction-modified TPU/PVDF composite film for human health and motion detection - Jiajie Du, Sixian Chen, Rui Ding, Yingpeng Wang, Qisong Shi (Polymer Bulletin, 2026)

Metal–Organic Framework Composite Piezoelectric Nanofibers for Wireless Tumor Treating Fields Therapy - Shiqin Dai, Ahmed Nabil, Yoshitaka Matsumoto, Muyasha Abulimiti, Yu Sugawara, Mitsuhiro Ebara (ACS Biomaterials Science & Engineering, 2026)
Glioblastoma (GBM) remains one of the most aggressive brain tumors, with limited treatment efficacy due to tumor invasiveness, drug resistance, and the blood-brain barrier. Tumor treating fields (TTFs) provide a non-invasive strategy by disrupting cancer cell mitosis using alternating electric fields, but current systems rely on external electrodes and suffer from low field penetration. By producing localized electric fields in response to mechanical stimulation, implantable piezoelectric nanofibers present a viable self-powered substitute. Here, we designed composite nanofibers by incorporating Mn-Ti bimetallic metal-organic framework (MT-MOF) into electrospun polyacrylonitrile (PAN) nanofibers. These composite nanofibers enhance piezoelectric output, enabling physiological motion-activated in situ TTFs generation for localized therapy without external wiring. Under ultrasound (US) stimulation, MT-MOF loaded nanofibers exhibits an output voltage of 0.35 V, generating adequate alternat ing electric fields to induce tumor apoptosis and ultimately promote cancer cell death. Good biocompatibility toward normal cells was demonstrated. In vivo experiments demonstrated that MT-MOF/PAN nanofibers effectively suppressed GBM tumor growth, highlighting their potential as a platform for implantable cancer treatment systems.

Nanoscale Mechanisms of Piezoelectric Enhancement in MXene–Fluoropolymer Composites - Kalyan Ghosh, Shaashwat Saraff, Sohini Kar-Narayan (Nano Letters, 2026)
Piezoelectric polymers have emerged as promising materials for flexible electronics, particularly in sensing and energy-harvesting applications. Their advantages over conventional inorganic piezoelectrics arise from their lower density, flexibility, ease of processing, and potentially lower costs. Many common piezoelectric polymers are bio-derived or biocompatible, making them ideal for applications in healthcare. The main disadvantage of piezoelectric polymers relative to inorganics is that their piezoelectric coefficients are usually a few orders of magnitude lower, and their low conductivity usually leads to piezoelectric nanogenerator (PENG) devices with very high output impedances, making interfacing with external circuits difficult. Among various strategies to improve the performance of piezoelectric polymers, the incorporation of two-dimensional MXenes as nanofillers has emerged as a versatile and effective approach. This Mini-Review summarizes the documented effects of MXenes o n piezoelectric fluoropolymers, with a focus on electrospun nanofibers. We discuss spatially confined nanostructures and interfacial interactions that lead MXene/polymer composites to exhibit enhanced performance. We highlight some MXenes that are inherently piezoelectric, while also discussing how conventional MXenes promote piezoelectricity in polymers, in addition to improvements in other areas, such as dielectric properties, charge transport, and mechanical properties. Finally, we outline future research directions for further enhancement techniques for the piezoelectric performance of MXene-based polymer composites.

Interfacial energy homogenization enables β-phase transition and high piezoactivity in MOF/PVDF membrane for sustainable pollutant degradation - Z L Yang, Miaomiao Tian, C X R CHEN, Z. Zhao, Libo Zhao, Jiujing Xu, Wei Y, Hongjun Lin (Chemical Engineering Journal, 2026)

Piezoelectric‐Conductive Hybrid Nanocomposite: PVDF/MWCNT Sensors for Smart Textiles - Mohadeseh Ramzanpour Nashrodkoli, Mostafa Jamshidi Avanaki, Aliakbar Gharehaghaji, Kamran Mahfouzi (Journal of Applied Polymer Science, 2026)
ABSTRACT The rapid expansion of smart textiles and wearable electronics has driven strong demand for flexible, durable, and multifunctional sensing materials capable of operating under continuous mechanical deformation. Among emerging candidates, Piezoelectric‐conductive hybrid nanocomposites based on polyvinylidene fluoride (PVDF) and multi‐walled carbon nanotubes (MWCNT) have attracted significant attention due to their unique ability to combine mechanical flexibility, Piezoelectric responsiveness, and electrical conductivity within a single material platform. This review provides a comprehensive analysis of PVDF/MWCNT hybrid systems for smart textile applications, covering material selection, Piezoelectric mechanisms, structural design strategies, fabrication techniques, and textile integration pathways. Key advances in β‐phase enhancement, conductive percolation, nanofiber alignment, hierarchical architectures, and hybrid filler synergy are critically discussed in relation to sensi ng performance, energy‐harvesting capability, durability, and wearability. Comparative evaluation with other PVDF‐based systems including ceramic‐filled, 2D‐material‐enhanced, and copolymer‐based composites highlights the balanced performance of PVDF/MWCNT hybrids in terms of sensitivity, flexibility, scalability, and textile manufacturability. Current challenges related to nanofiller dispersion, durability, environmental stability, and sustainability are also addressed. Overall, the reviewed results demonstrate that PVDF/MWCNT hybrid nanocomposites represent one of the most promising material platforms for next‐generation smart textiles, enabling reliable physiological monitoring, motion sensing, and self‐powered wearable systems integrated within fabric‐based architectures.

Wearable Music Tuning Ring for the Concert Pitch Using PVDF/BCZT Piezoelectric Composites - Mengchen Zhou, T B Zhang (Polymers, 2026)
Instrument tuning is crucial for the performance quality of orchestral concerts. In most cases, the standard pitch is usually given by the oboist, and then the rest of the orchestra adjusts their instruments to match it. However, in the individual training scene, music instrument players often rely on a piano or a pitch pipe for the standard pitch. The piano is not portable, and the pitch pipe could be inaccurate. Therefore, a portable, accurate and user-friendly tuning device is urgently required. In this work, we sought to design a wearable music ring using high-performance PVDF/BCZT composites to stimulate the standard pitch when needed anywhere and anytime. In the music ring, there are two core buttons that stimulate and modulate the output voltage and create the standard pitch. To optimize the performance, we constructed a composite structure, with BCZT particles embedded in highly oriented polyvinylidene fluoride (PVDF) fibers. The composite presents an aligned fiber structure, w hich endows it with high piezoelectricity. It presents sensitivity as high as 0.12 V N−1 and remains stable after 10,000 cycles at 1 Hz. Furthermore, the volume of the standard pitch could be modulated by switching the buttons on the wearable music ring, which meets real application needs. This research presents a protocol showing a typical application of wearable technology, which not only shapes the development of flexible electronics but also redefines the tuning experience for musicians.

Fabrication of Piezoelectric Energy Harvester Using Polyvinylidene Fluoride Through Solution Casting Method - Pradipta Sarmah, Mohd. Anis Ansari, Alfa Bisoi (physica status solidi (a), 2026)
This research emphasizes the fabrication of a sustainable energy harvesting system through the piezoelectric energy harvester (PEH) using polyvinylidene fluoride (PVDF) with the addition of ionic liquid (IL) to improve its piezoelectric properties. The PEH is designed to convert mechanical vibrations into electrical signals. PVDF/IL composite is formed using the solution casting technique, followed by the thermal evaporation of copper electrodes onto the surface of the PEH to ensure efficient charge capture. The open‐circuit voltage generated by the harvester was measured with a multimeter. An amplifying circuit utilizing an operational amplifier IC 741 was also constructed to further enhance the output voltage signal from 190 mV to 2.13 V, enhancing the measurable voltage output signal for sensing. This work not only showcases the potential of PVDF‐based piezoelectric materials for sustainable energy solutions but also lays the groundwork for future implementations, including the inte gration of this technology in self‐powered sensors, contributing to the advancement of energy‐efficient systems in various applications.

Synergistic Enhancement of Hybrid Piezoelectric-Triboelectric Nanogenerator via Morphological and Polarization Engineering of NaNbO 3 Nanostructures - Arn Er Soh, Qianyuan Woo, Jason Soon Chye Koay, Sanjeev R. Gopal, Wee Chen Gan, Thamil Selvi Velayutham (ACS Applied Electronic Materials, 2026)
Hybrid piezo/triboelectric nanogenerators (H-P/TENGs) are highly effective for mechanical energy harvesting; however, while existing literature heavily focuses on traditional piezoelectric polymers or bulk binary ceramics, the specific role of lead-free filler morphology remains largely unexplored. This study addresses this gap by systematically isolating the roles of morphology and polarization using lead-free sodium niobate (NaNbO 3; NNO) nanostructures within a polydimethylsiloxane (PDMS) matrix. We evaluated four distinct geometries; nanowires, nanocubes, and their sonicated counterparts. The cubic morphologies consistently outperform wire-like structures due to their superior crystallinity and higher dielectric and piezoelectric properties. Additionally, mechanical sonication resolved the typical trade-off between filler loading and surface roughness, maximizing the effective contact area for triboelectric electrification. Kelvin probe force microscopy (KPFM) and an overlapped ele ctron cloud model reveal that forward polarization optimizes performance by lowering the composite work function, which enhances electron transfer during contact. Under the optimal configuration of 5 wt % sonicated nanocubes and forward polarization, the device achieved a peak power density of 5.25 W/m 2 (a six-fold improvement over the pristine matrix) and successfully powered a commercial scientific calculator. These findings establish filler geometry, morphology, or any other filler-related properties as clear design rules for high-performance, lead-free hybrid nanogenerators.

Effect of barium titanate nanoparticles on pore architecture and early-stage chondrocyte response in breath figure–derived PLDLA scaffolds - H. Karjalainen, V.P. Karjalainen, G.S. Lorite, M. Hannula, T. Siponkoski, M. Nelo, J. Juuti, A. Mobasheri (Next Materials, 2026)
A suitable microenvironment is essential for chondrocytes to maintain their phenotype and extracellular matrix (ECM) production during long-term in vitro culture. Pore structure, interconnectivity, and the ability to provide natural cellular cues are important properties in the scaffolds. Additionally, piezoelectric materials such as barium titanate can provide electromechanical stimulation to influence cellular behaviour. This study investigated the effect of the barium titanate nanoparticles (BTNP) on pore formation in poly-L/ D -lactide copolymer (PLDLA) scaffolds fabricated using the breath figure method. The final nanoparticle content, pore structure, and interconnectivity were characterised. Human articular chondrocytes were cultured on the scaffolds for two weeks to evaluate cytotoxicity, cell proliferation, cell morphology, and ECM production. The micropatterned porous structure was maintained across all PLDLA/BTNP scaffolds (BTNP content: 0, 10, 20, 30, and 40 wt%). X-ray micr otomography (XRM) was able provided insight into pore structure and interconnectivity of the scaffolds. Pore diameter increased in the PLDLA/BTNP scaffold to approximately 20 µm, while in the PLDLA scaffolds, it was 2 µm. All PLDLA/BTNP scaffolds were non-cytotoxic, and cells were more spherical in the PLDLA/BTNP scaffolds, but there was no difference in ECM production. Overall, the amount of BTNPs influenced the scaffold structure. These early-stage findings demonstrated that scaffolds were non-cytotoxic and exhibited a porous architecture conducive to cell growth and maintenance. These findings highlight the potential of the developed PLDLA/BTNP scaffolds as three-dimensional platforms for long-term in vitro studies, enabling the investigation of cellular behaviour and cell–material interactions under physiologically relevant conditions.

Field‐Programmed Anisotropy in Magneto‐Piezoelectric Composites for Material‐Encoded Mechanoperception - Yubin Kim, Yumin Kwon, Dabin Kim, Minsun Oh, Joo‐Ho Jung, Dongyeong Gim, Kootak Hong, Jun Yeon Hwang (Advanced Materials, 2026)
ABSTRACT Decoupling superposed force vectors along spatially distinct axes is a prerequisite for artificial somatosensation in soft intelligent systems. Although polymer‐piezoelectric composites offer essential compliance, randomly distributed nanofillers result in a loss of inherent polar directionality and macroscopic anisotropy, which prevents force‐vector discrimination. Here, we address this challenge by encoding force‐mode selectivity into magneto‐piezoelectric composites via field‐programmed anisotropy. Guided by a rigorous torque‐balance framework, we achieve the deterministic spatial alignment of Fe 3 O 4 ‐decorated BaTiO 3 nanowires within a shape‐memory polymer matrix. The resulting axially aligned hierarchical percolation networks serve as continuous load‐transfer pathways to concentrate mechanical stress along the principal axes of the nanowires while suppressing off‐axis interference. Such structure‐driven anisotropy in electromechanical coupling maximizes piezoelectric t ransduction efficiency and empowers the nanocomposite to intrinsically distinguish force modalities. By upscaling the intrinsic anisotropy of piezoelectric nanowires to the macroscopic composite level, our approach defines a physical basis for material‐encoded mechanoperception. Our findings establish a versatile platform for soft embodied intelligence that offers vector‐resolved somatosensory capabilities at the material level.

Superior Piezocatalytic Activity and Environmental Adaptability in Micro‐Nano‐Engineered BaTiO 3 /PVDF@Ag Composite Structure - Bing Xie, Wenpeng Gao, Liu Zh, Kun Guo, Qingping Wang, Shenglin Jiang, Chris Bowen, Huajie Luo (Advanced Functional Materials, 2026)
ABSTRACT Piezocatalysis, the direct conversion of mechanical energy into chemical reactivity, offers a promising route for sustainable pollutant removal and chemical synthesis. However, practical applications require materials that are able to simultaneously deliver high activity, stability, and ease of recycling. Here, we report a flexible micro‐nano‐engineered BaTiO 3 /PVDF@Ag composite film, whereby {111} BaTiO 3 single‐crystal microsheets are embedded in a poly (vinylidene fluoride) (PVDF) matrix and decorated with photo‐deposited Ag nanoparticles. This BaTiO 3 /PVDF@Ag composite microstructure design endows the optimal composite with outstanding piezocatalytic performance, including a Rhodamine B degradation rate constant of 0.24 min −1 , a hydrogen peroxide generation rate of 3520 µmol g −1 h −1 , and a CO 2 reduction rate of 535 µmol g −1 h −1 , while maintaining its activity over repeated cycles. Systematic structural, spectroscopic, and electrochemical characterization, togeth er with theoretical simulations, reveal that the ferroelectric BaTiO 3 and electroactive β ‐phase PVDF enhance the local piezoelectric potential under mechanical stimulation, while the Ag nanoparticles act as efficient electron traps and catalytic sites. Interfacial polarization as resulting from the dielectric and conductivity mismatches between the composite components also reduces charge‐transfer resistance and thereby accelerates carrier separation and migration. These synergistic effects enable efficient formation of reactive oxygen species, thereby driving high H 2 O 2 yields and CO 2 reduction. The mechanically robust film can also be easily recovered and reused, demonstrating a viable route to green, high‐performance piezocatalysts for environmental applications.

Synergistic β-Phase Enhancement in PVDF – AlN – Yttrium (PAY) Nanocomposites for Flexible Low-Frequency Biomedical Piezoelectric Energy Harvesting - Pushplata Tiwari, A A Brazil Raj, Mamta Devi, Sunny Sharma, Surya Prakash (Polymer-Plastics Technology and Materials, 2026)
In this study, a PVDF – AlN – Yttrium (Y3+) tri-composite nanofibrous system was developed through sol – gel-assisted electrospinning to enhance β-phase nucleation and piezoelectric energy conversion. The novelty of the work lies in the complementary use of 10 wt% AlN nanoparticles and 5 wt% Y3 + species within the PVDF matrix, where AlN promotes heterogeneous nucleation and interfacial polarization, while Y3 + induces ion – dipole interactions with – CF2 dipoles. Annealing at 140°C followed by corona poling at 26 kV and 80°C further stabilized the electroactive β-phase. FTIR and XRD analyses confirmed 84.13% β-phase fraction and 72% crystallinity for the optimized PA10%Y5% composition. FESEM observations revealed dense, bead-free, and uniform nanofiber morphology with improved filler dispersion. The optimized nanocomposite exhibited a d33 value of 28 pC/N, dielectric constant of 17, open-circuit AC voltage of 17.6 V, and short-circuit current of ~140 µA, corresponding to a maximum AC power output of ~ 595 µW. After rectification, the device delivered ~11.77 V DC and ~286 µW maximum DC power. The silicone-encapsulated PVDF – AlN – Y3 + nanocomposite demonstrates potential for flexible low-frequency biomedical energy-harvesting applications.

Effect of BaTiO3 Additives on β-Phase Formation and Enhanced Piezoelectric Behavior of PVDF - Ibtisam Yahya Abdullah (Journal of Electronic Materials, 2026)

Flexible MoS 2 ‐ CNCs / PVDF Piezoelectric Composites With Enhanced Crystalline Phase Transition for Robust Physiological Signal Monitoring - Xiang Chen, Xun Luo, M. Q. Zhang, Xiwen Qiu, Fan Meng, Chenglong Wang, Han Zhu, Jinhuan Zheng (Journal of Applied Polymer Science, 2026)
ABSTRACT Two‐dimensional (2D) piezoelectric semiconductors, specifically molybdenum disulfide (MoS 2 ), have emerged as premier candidates for next‐generation nanoscale tactile sensors due to their exceptional electron mobility, high polarization rates, and low power consumption. However, the inherent rigidity and structural brittleness of MoS 2 hinder its seamless integration into flexible, wearable platforms. Herein, we report a synergistic strategy combining mechanical ball milling and electrospinning to fabricate high‐performance MoS 2 carbon nanocrystal/polyvinylidene fluoride (MoS 2 ‐CNCs/PVDF) nanofibrous membranes on textile substrates. By utilizing polyvinylpyrrolidone (PVP) as a macromolecular surfactant, we achieved superior filler dispersion and optimized interfacial bonding within the polymer matrix. At an optimal PVP concentration of 10%, the composite exhibits a piezoelectric coefficient ( d 33 ) of 34 pC/N—a 1.3‐fold increase over pristine PVDF and delivers a peak outpu t voltage of 2.12 V under a 0.5 N load with high linearity ( R 2 > 0.93). Furthermore, the hierarchical composite architecture yields robust mechanical properties, including a tensile strength of 19 MPa and 100% elongation at break, effectively overcoming the traditional brittleness of inorganic MoS 2 systems. Integrated into elastic textiles, the resulting sensor enables high‐fidelity real‐time monitoring of physiological signals, including radial pulse, respiratory rhythms, and joint kinematics. This work provides a scalable pathway for health diagnostics and human‐machine interaction.

Material Extrusion‐Enabled Soft Multimodal Pressure Sensors With Fabrication‐Embedded Stretch‐Induced Strain Insensitivity - Jinsheng Fan, Shujia Xu, Yi Yang, David Harmon, Yuelin Deng, Brittany Newell, Wenzhuo Wu, Robert A. Nawrocki (Small, 2026)
ABSTRACT Key challenges in stretchable pressure sensors include establishing cost‐effective fabrication routes for soft functional materials, achieving strain‐insensitive performance under deformation, and enabling seamless integration into soft architectures. Here, electrospinning is combined with liquid‐based material extrusion ( l ‐MEX) and melt‐based material extrusion ( m ‐MEX) to fabricate stretchable pressure sensors with multimodal sensing capability. The sensing layer is composed of mechanically anisotropic electrospun poly(vinylidene fluoride) / thermoplastic polyurethane composite microfibers sandwiched between l ‐MEX printed stretchable silver electrodes, exhibiting a Young's modulus as low as 0.5 MPa. A three‐dimensional serpentine architecture reconfigures the sensing layer into a compliant geometry and enables system‐level stretchability while maintaining stable sensing performance under strain. In the capacitive mode, the optimized sensor achieves 97.6% strain insensiti vity under strains up to 30% and a minimum detectable pressure of 0.04 kPa. In the piezoelectric mode, the same device exhibits a sensitivity of 16.5 mV kPa −1 and a strain‐insensitivity ratio of 85.4% at 10% applied strain. A stretchable capacitive sensing matrix enables uniform pressure mapping under strain. Integration of the sensors into a pneumatically actuated soft gripper further demonstrates real‐time piezoelectric responses. This work presents a scalable and automatable manufacturing route for integrating soft functional materials into stretchable electronics and soft robotic systems.

A skin-adhesive bimodal sensing patch for occlusal function assessment - Longchao Huang, Ruoxi Li, Xuelan Li, Yue Sun, Shenglong Wang, Boling Lan, Guanfa Li, Long Jin (npj Flexible Electronics, 2026)
Occlusal dysfunction is a prevalent orofacial disorder characterized by aberrant occlusal force transmission and dysregulated masticatory muscle activity. Currently, quantitative characterization of occlusion-related neuromechanical activity remains challenging in clinical practice. In this study, we propose a skin-interfaced bimodal sensing patch that integrates serpentine-structured piezoelectric poly(vinylidene fluoride) (PVDF) films with conductive hydrogel electrodes for simultaneous monitoring of facial skin deformation and muscle electrophysiology during occlusal activities. The island-serpentine design ensures high mechanical compliance while preserving stable electromechanical performance over more than 14,000 loading cycles. The hydrogel interface serves not only as an adhesive layer ensuring conformal adhesion of the PVDF film to the skin but also functions as a low-impedance electrode, enabling high-fidelity surface electromyography (sEMG) acquisition with a signal-to-noise ratio of ~30 dB. Through combined analysis of piezoelectric and sEMG signals, the system distinguishes functional occlusal actions, including normal occlusion, deep overbite, crossbite, and mandibular deviation. This bimodal framework provides a preliminary proof-of-concept for multimodal functional characterization of occlusal biomechanics and suggests potential applicability in noninvasive occlusal function assessment.

Piezoelectric Bioactive Drug‐Based Supramolecular Assemblies Toward Health Monitoring and Wound Healing - Xiaoyu Tong, Yuanhao Sun, Shuaijie Liu, Yehong Huo, Li Li, Y H Yin, Xiaohui Xu, Jinlin Song (Advanced Materials, 2026)
ABSTRACT Bioactive molecules can self‐assemble to form noncentrosymmetric supramolecular materials exhibiting piezoelectric response. However, the piezoelectricity of antibiotic‐based molecular assemblies has been largely unexplored. The understanding of the structure‐piezoelectricity relationship of bioactive molecular assemblies will facilitate the rational design of multifunctional piezoelectric materials. Herein, for the first time, we systematically investigated the piezoelectricity of bioactive β‐lactam drug‐based supramolecular assemblies, further revealing the piezoelectric‐antibacterial synergy of electronic devices. X‐ray diffraction analysis revealed that the supramolecular assemblies of different β‐lactam drugs exhibited diverse ordered packing modes. Their maximum piezoelectric coefficients showed a broad range of 3.2–44.3 pC N − 1 as calculated by density functional theory, in which faropenem sodium (FarNa) crystals displayed the highest value due to a highly asymmetric s tructure and a large dipole alignment. The FarNa crystal‐based piezoelectric device generated an open‐circuit voltage of up to 1.08 V and was successfully integrated into a flexible sensor for rehabilitation monitoring. Furthermore, the piezoelectric response of composite films loaded with amoxicillin (AMX) or FarNa crystals could disrupt bacterial cell membranes, enhancing antibacterial activity and infected wound healing. This work explores the piezoelectric response of β‐lactam drug‐based assemblies, leveraging a supramolecular assembly strategy to develop biomaterials with coupled piezoelectric and biological functions.

Revealing the Giant Electromechanical Effects in Yttria‐Stabilized Zirconia Single Crystal - Zhuwu Yi, Kai Pan, Chaoming Hu, Luocheng Liao, Zhijian He, Ziwei Guo, Yibao Wu, Changxing Zhao (Advanced Science, 2026)
ABSTRACT Ionic conductors exhibiting giant electromechanical responses have emerged as promising alternatives to lead‐based relaxor ferroelectrics for high‐resolution actuators and sensors. However, the role of long‐range oxygen‐vacancy migration in governing electromechanical properties remains unclear and even controversial. Yttria‐stabilized zirconia single crystal (SC‐YSZ) provides an ideal model system to elucidate the origin of electrostriction and piezoelectricity with oxygen‐vacancy migration, owing to the absence of grain boundaries and substrate constraints. Here, atomic force microscopy (AFM) is employed to probe the electromechanical coupling responses of SC‐YSZ, displaying pronounced orientation‐dependent features and non‐intrinsicity in [100]‐, [110]‐, and [111]‐oriented SC‐YSZs. Notably, the giant electrostrictive coefficient | M 33 | of 5.82 × 10 −17 m 2 V −2 and remarkable pseudo‐piezoelectric coefficient | d 33 | of 218 pm V −1 are obtained at the frequency of 10 mHz in [100]‐oriented SC‐YSZ. Local relaxation measurements, macroscopic ionic conductivity, and first‐principles calculations reveal that the orientation‐dependent electrostrictive and pseudo‐piezoelectric responses arise from the long‐range migration of oxygen vacancies, governed by direction‐dependent migration difficulty under electric fields. This work provides direct evidence linking giant electromechanical responses with long‐range oxygen‐vacancy migration, and highlights that such effects in SC‐YSZ cannot be neglected when employed as substrates or composite layers in electroactive materials and device systems.

A Sandwich‐Structured Piezoelectric Elastomer Containing a Porous Core Layer for Improving Output Performance - Hancong Zheng, Zhefeng Liu, Tianhao Chen, Yongbin Zhao, Aihua Chen (Small, 2026)
ABSTRACT Driven by the rapid development of portable and miniaturized electronics, flexible polymer‐based piezoelectric nanogenerators (PENGs) have attracted significant attention for stable energy harvesting and self‐powered sensing. However, developing materials that simultaneously combine high elasticity with superior piezoelectric output remains fundamentally challenging, owing to the intrinsic trade‐off between mechanical compliance and electromechanical coupling. Herein, we demonstrated a sandwich‐structured piezoelectric elastomer (STPPE) featuring a porous thermoset polyurethane (TSPU)/P(VDF‐TrFE)/PZT core (TPP) and solid TSPU/P(VDF‐TrFE) skin layers through a combined approach of physical foaming and laminated structural engineering. By tuning the foaming agent content and curing temperature, the porous morphology can be effectively modulated to optimize the porosity, electroactive phase (β‐phase) content, and mechanical properties. The STPPE exhibited a substantially enhanced piezoelectric performance, achieving a V oc of 62.1 V, a Q of 11.6 nC, a sensitivity of 3.82 V·kPa −1 under 13 N. At 100 N, the output surged to 80.1 V and 44.7 nC, respectively. A power density of 2.6 µW·cm −2 was achieved, alongside a highly stable electrical output over 10 000 cycles, demonstrating the promising potential for practical applications. This work presents a robust strategy for fabricating high‐performance, lightweight, and elastic piezoelectric composites for next‐generation wearable electronics and self‐powered sensors.

Interfacial Polarization Engineering via One‐Dimensional Ionic Crystal Fibers for High‐Performance Triboelectric and Piezoelectric Nanogenerators - Bingqi Ren, Jingzhe Sun, Seunghye Han, Zihao Zheng, Hyemin Bak, Seohyeon Lee, Yongwei Li, Kyoung‐Seok Moon (Small, 2026)
Enhancing the dielectric properties of polymer composites through particulate inorganic fillers 0D has been widely explored as an effective strategy to improve the energy-harvesting performance of triboelectric and piezoelectric devices. Compared with conventional particulate fillers, 1D fillers offer intrinsic structural anisotropy and enlarged polymer-filler interfaces that favor interfacial polarization and charge transport. However, the intrinsically isotropic crystallization behavior of inorganic salts hinders the formation of long-range ordered 1D structures, leaving one-dimensional inorganic salt fibers largely unexplored as functional fillers. Here, we propose a template-guided directional crystallization strategy to construct 1D potassium chloride (KCl) fibers as functional fillers. The resulting fibers reach macroscopic lengths of up to ∼6 cm and retain continuous crystalline morphology within polymer matrices, thereby enabling extended polymer-filler interfaces. As a result, the fiber-based composites exhibit enhanced dielectric performance over particle-filled composites. Multi-scale characterization reveals that the 1D fibrous structure promotes interfacial polarization and guides dipole alignment within the polymer matrix. Furthermore, the fiber-enhanced PENG was integrated into a wearable sensing platform for real-time monitoring and recognition of human motion with machine learning. This work demonstrates that one-dimensional inorganic salt fibers, as functional fillers, provide an effective strategy for enhancing interfacial polarization in flexible energy-harvesting systems.

Poly(vinylidene fluoride)/2D Layered Molybdenum-Based MXene Composite for Piezoelectric and Piezocatalytic Applications - Komal Kukreja, Shewli Pratihar, Prasanta K Panda, Prasanna Kumar S. Mural (ACS Applied Electronic Materials, 2026)
Poly(vinylidene fluoride) (PVDF)-based piezoelectric nanogenerators (PENGs) have emerged as sustainable and lightweight materials for mechanical energy harvesting; however, their performance is often limited by insufficient electroactive phase content and weak interfacial polarization. In this work, we report the fabrication of flexible PVDF-based PENGs enhanced with 2D Mo-based MXene, used as controlled nucleating fillers. Comprehensive structural, thermal, dielectric, ferroelectric, and piezoelectric analyses of pristine PVDF and its nanocomposites revealed that the PVDF film containing 1 wt % MXene (P-1M) exhibits better functional performance suitable for nanogenerator applications. Piezoresponse force microscopy verified a high piezoelectric coefficient ( d 3 3 ≈ 27 pm/V) for the P-1M sample. The incorporation of MXene effectively induced electroactive phase formation in PVDF. The PVDF/MXene nanocomposite-based PENG demonstrated a power output of 15.86 μW under a periodic load of 25 N, generating a peak-to-peak voltage of 20 V and a current of 1.84 μA. The optimized device successfully powered light-emitting diodes, charged capacitors, and detected various human motions. Moreover, the as-fabricated film exhibited notable piezoelectric activity at different pressures with a sensitivity of 0.24 V/kPa in the low-pressure range and rapid response and recovery times of 6 and 27 ms, respectively, without the need for additional poling. Apart from this, the nanocomposite film demonstrated a piezocatalytic response by achieving 97% degradation of Rhodamine B dye through the production of reactive oxygen species under mechanical stress. Overall, these results show the multifunctional applications of PVDF@Mo-MXene nanocomposites in biomechanical energy harvesting, motion detection, powering of next-generation self-sustained electronic and sensing devices, and energy harvesting from waterfalls and water purification.

Two-dimensional pressure mapping using a porous PVDF film with orthogonal stripe electrodes - Daisuke Tadaki, Teng Ma, S Matsumoto, Shin Yamamiya, Yuji Imai, Ayumi Hirano‐Iwata, Michio Niwano (Sensors and Actuators A Physical, 2026)
ABSTRACT Flexible and wearable pressure sensors are essential components for next-generation healthcare monitoring, human–machine interfaces, and artificial skin applications. In particular, two-dimensional pressure mapping sensors capable of spatially resolved measurements are required for tactile sensing and motion analysis. However, most existing pressure mapping sensors rely on rigid inorganic materials and complex microfabrication processes, limiting their applicability in flexible systems. This paper presents a flexible two-dimensional pressure mapping sensor based on polyvinylidene fluoride (PVDF) and a simple orthogonal wire-electrode architecture. A uniformly deposited PVDF film is sandwiched between two layers of metal wire electrodes with a width of approximately 150 μm, enabling pressure distribution measurements with a spatial resolution of 200 μm. Unlike previously reported flexible pressure mapping sensors that employ microfabrication or nanostructured sensing layers, th e proposed device is fabricated using a low-temperature, solution-based PVDF deposition process, resulting in a simple, scalable, and cost-effective structure. The pressure response characteristics of the sensor were experimentally evaluated, demonstrating stable and repeatable piezoelectric output under applied normal pressure. The pressure sensing mechanism of the proposed mapping sensor is also discussed. Owing to its mechanical flexibility, simple fabrication, and high spatial resolution, the proposed PVDF-based pressure mapping sensor is promising for wearable sensing and tactile interface applications.

Grafting‐Induced Dual Electric Fields in Metal–Organic Frameworks for Efficient Piezo‐Photocatalytic CO 2 Reduction - Jingce Bi, Yan Qian, Qingfeng Zhan, Huichun Xue, Ningning Liu, Xia Zhang, Zhuopeng Wang, Lin Zhu (Small, 2026)
ABSTRACT Metal‐organic frameworks (MOFs), a class of porous crystalline materials with tunable coordination structures, offer unique opportunities for CO 2 photoreduction; however, their application in piezo‐photocatalysis remains limited by poor visible‐light absorption, high structural symmetry, and low polarity. Herein, we report a CN‐grafting strategy that anchors carbon–nitrogen (CN) species onto coordination‐unsaturated Ni sites of Ni‐BDC, constructing NiM‐CN with a grafting‐induced internal electric field (IEF). This modification enhances the structural asymmetry and polarity, thereby strengthening piezoelectric polarization and generating a polarization‐induced electric field (PEF) under mechanical stimulation conditions, as demonstrated by the increased piezoelectric coefficient (d 33 , from 42.41 to 82.16 pm V −1 compared to the reference sample). Meanwhile, CN grafting narrows the band gap and strengthens the IEF in NiM‐CN through Ni 3d–N 2p orbital hybridization and asymmet ric charge redistribution. The synergistic effect of IEF and PEF accelerates charge separation and transfer, leading to enhanced surface charge accumulation, as confirmed by in situ Kelvin probe force microscopy (KPFM). Consequently, NiM‐CN achieves a remarkable CO production rate of 3406.36 µmol g −1 h −1 under piezo‐photocatalytic conditions. This work establishes grafting‐induced IEF engineering as an effective strategy for constructing coupled electric‐field systems in MOFs for efficient piezo‐photocatalysts.

A topologically engineered honeycomb-like (2-0)-2 piezoceramic composite ultrasonic transducer with superior sensitivity - Lei Y, Xiaotian Li, Guohong Gan, Wei Bai, Bing Wang, Ziyan Gao, Xinyi Zheng, Xiangmeng Lv (Applied Physics Letters, 2026)
Piezoelectric ultrasonic transducers (PUTs) are widely utilized across a variety of technological fields; however, further advancement in ultrasonic transducer performance faces fundamental limitations. Herein, we report a brand-new (2-0)-2 piezoelectric ceramic composite (PCC) for enhancing sensitivity, featuring a topologically engineered honeycomb-like piezoceramic plate architecture [termed the (2-0) phase] uniformly embedded within the epoxy resin matrix (2-phase). This unprecedented novel structure effectively decreases the relative permittivity, acoustic impedance, and stiffness of the ceramic composite, while preserving the intrinsic main piezoelectricity and restraining the transverse piezoelectric effect. The resulting PCC shows a hydrostatic figure of merit (HFOM) dhgh of 3784.1 × 10−15 m2/N, representing a 312.3% improvement compared to that of the conventional 2-2 type PCC. Experimental results validate the performance enhancements of the (2-0)-2 PCC-based PUT, including a −6 dB transmitting bandwidth of 130 kHz, a higher transmitting voltage response and receiving voltage sensitivity, and an output voltage that is 46.4% higher than that of the conventional 2-2 composite transducer under identical excitation conditions. This proposed design strategy offers valuable guidance for the development and optimization of next-generation piezocomposite materials and high-sensitivity ultrasonic transducers.

Multifunctional Hydroxyapatite–Barium Titanate Coatings with Green-Synthesized Silver Nanoparticles for Orthopedic Implants: Piezodynamic, Biological, and Antibacterial Evaluation - Roberto Gómez Batres, Irene Leal‐Berumen, Oscar Morales, Claudia A. Ramírez-Valdespino, Marco Ruiz-Esparza-Rodríguez, OSCAR SOLÍS-CANTO, Antonio Ledezma‐Pérez, Anabel D. Delgado (Coatings, 2026)
Infection associated with orthopedic implants remains a major challenge in the development of biomimetic materials for bone tissue engineering. Surface modification strategies are widely employed to transform bioinert metallic substrates into bioactive interfaces that promote tissue integration while preventing bacterial colonization. This study investigated the effect of incorporating silver nanoparticles (nAg) into hydroxyapatite–barium titanate (HA–BT) coatings on their structural, mechanical, piezoelectric, biological, and antibacterial properties. Raw materials were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM), whereas coatings were evaluated by XRD, scanning electron microscopy (SEM), tensile adhesion testing, electrochemical analysis, piezoresponse force microscopy (PFM), cell viability, and antibacterial assays. The coatings exhibited secondary phases, including β-tricalcium phosphate (β-TCP), tetracalcium phosphate (TTCP), and calcium oxi de (CaO), generated during atmospheric plasma spraying (APS), while no silver oxide phases were detected after nAg incorporation. SEM observations revealed homogeneous phase distribution and strong coating–substrate adhesion. The addition of nAg did not significantly affect adhesive strength (44.58 ± 2.2 MPa for HA30BT and 43.28 ± 2.8 MPa for HA30BT–nAg). Protein adsorption studies indicated moderate albumin affinity (Kads = 0.45) for nAg-containing coatings. Both coatings exhibited piezodynamic activity with d33 values of approximately 13 pm/V. MTT assays confirmed non-cytotoxic behavior, with viability reductions below 2%. Osteocalcin expression demonstrated comparable osteogenic activity in coatings with and without nAg, regardless of low-intensity pulsed ultrasound stimulation. These findings highlight the potential of HA–BT–nAg coatings as multifunctional surfaces for bone regeneration and infection prevention.

1‐1‐3‐Type Piezoelectric Composite Materials: Design, Fabrication, and Thickness Vibration Characteristics Analysis - Qiguo Huang, Mingyang Wang, Yiqiang Wu, Song Shuaigang, Qinyuan He, Huayang Sai, Zhouhui Tuo (International Journal of Applied Ceramic Technology, 2026)
ABSTRACT Monolithic piezoelectric ceramics suffer from severe modal crosstalk and parasitic vibration interference, while conventional 1–3 piezoelectric composites are constrained by cumbersome fabrication procedures and limited structural flexibility. This work proposes a novel 1‐1‐3‐type piezoelectric composite fabricated via stereolithography 3D printing and precision assembly. The composite under consideration is composed of polarized PZT piezoelectric pillars, the silicone rubber bonding component, and the 3D‐printed resin framework. A theoretical analysis and COMSOL simulation are conducted to investigate its vibration and resonant characteristics. Experimental results demonstrate that the composite achieves pure thickness‐mode resonance at 466.5 kHz, effectively eliminating modal crosstalk. Compared with monolithic ceramic, including an effective electromechanical coupling coefficient of 0.69, and dielectric loss decreases by 31.05%. The average resonant frequency deviation betw een simulation and experiment is only 4.08%, confirming high fabrication repeatability. This work provides a scalable fabrication strategy for high‐performance piezoelectric composites in ultrasonic sensing applications.

Sustainable P3HB:ZnO Composite Piezoelectric Nanofibers for AI‐Driven Gait Monitoring - Milad Razbin, Kexin Ruan, Danish Tahir, Xuan Li, Qing Li, Hala Zreiqat, Fariba Dehghani, Shuying Wu (Small Science, 2026)
Degrable, high‐performance piezoelectric materials are critical for implantable and environmentally friendly devices capable of reliable sensing and energy harvesting while safely degrading after use. However, most degrable piezoelectric materials still suffer from limited electromechanical performance. Here, we report a high‐performance poly(3‐hydroxybutyrate):zinc oxide (P3HB:ZnO) composite piezoelectric nanofiber optimized using an integrated artificial neural network‐genetic algorithm framework. The model identified an optimal ZnO content of 4.3 wt.%, resulting in significantly enhanced piezoelectric performance compared with pristine P3HB. The optimized nanofibers achieved a peak voltage sensitivity of 0.382 mV/kPa at 1 Hz and an effective piezoelectric voltage coefficient of 13.65 mV/m·N, with stable output over 1000 loading cycles and a response delay of 318 ms. Biodegradation studies showed approximately 38% mass loss after 6 weeks, while the nanofibers retained measurable piez oelectric functionality within this timeframe. Furthermore, integration with a multichannel sensing platform enabled a proof‐of‐concept AI‐assisted gait‐recognition demonstration. This work presents a scalable machine‐learning‐driven strategy for designing high‐performance sustainable piezoelectric materials for self‐powered transient bioelectronics.

Machine learning-driven fiber steering of variable-stiffness piezoelectric composites for vibration energy harvesting - Abdelatif Salmi, Geeta Devi (Next Materials, 2026)
Autonomous wireless sensing for structural-health monitoring and Internet-of-Things applications increasingly demands battery-free power sources, motivating the conversion of ambient mechanical vibration into usable electrical energy. This study introduces an interpretable machine-learning framework for designing variable-stiffness piezoelectric composite vibration energy harvesters, in which curvilinear (tow-steered) fibers provide a continuous means of tailoring both the resonant frequency and in conjunction with the electrode layout, the harvested power. A coupled electromechanical first-order shear-deformation finite-element model, using the MITC4 formulation to suppress shear locking, is developed and verified against analytical plate solutions and an established distributed-parameter harvester benchmark. A 1200-sample Latin-hypercube dataset spanning the fiber path, plate geometry and electrical load is used to train four surrogates Gaussian process regression, random forest, gra dient boosting and a multilayer perceptron for the fundamental frequency, peak power and volumetric power density. Gaussian process regression is the most accurate (R 2 ≈ 0.998). A SHAP analysis, cross-validated by permutation importance, identifies the governing variables, and a surrogate-driven Pareto optimization balances power density against resonance matching. Through a fully controlled comparison at fixed geometry, mass and resonance, fiber steering is shown to provide essentially no benefit with a full-coverage electrode but to increase peak harvested power by up to about 10% once the electrode is localized near the clamped root, by concentrating the modal strain where the charge is collected; all designs are revalidated by direct finite-element analysis to within 3%. Fiber steering and electrode geometry must therefore be co-designed—an interpretable guideline for variable-stiffness piezoelectric-based vibration energy harvesting.

Textured Piezoelectric Ceramics Printed With Baffled Nozzles - Christopher Eadie, Jules W. Lindau, Benjamin E. Cowen, Chloe A. Fellabaum, Beecher H. Watson, Mark A. Fanton (Journal of the American Ceramic Society, 2026)
ABSTRACT This study aims to enhance additive manufacturing of ceramics with crystallographically aligned microstructures, known as textured ceramics. Additive manufacturing is pursued because it addresses limitations of the current standard process, tape casting. However, circular nozzles typical of the direct ink writing (DIW) process fail to align particles effectively, resulting in poor alignment and suboptimal properties. To address this, we investigate nozzles with internal baffles for orienting (BT) platelets in a lead magnesium niobate‐lead zirconate titanate (PMN‐PZT) ceramic paste. Nine nozzle designs were assessed using computational fluid dynamics (CFD), and printed parts were characterized for texture quality and piezoelectric properties. Smaller outlet gap heights and additional baffles improved texture quality, with the aspect‐ratio‐16, three‐baffle nozzle being most effective, achieving properties on par with tape cast material and consistent with CFD predictions. Tradit ional texture characterization using X‐ray diffraction (XRD) with the Lotgering factor (LF) was laborious and less correlated with piezoelectric coefficient than microstructural analysis. A Gaussian‐process‐based algorithm was used to digitally optimize nozzle geometry and print speed using the CFD model, which converged on a design favoring maximal print speed and nozzle length, with minimal height and width.

Comparative assessment of CPC and PZT sensor embedding strategies via FFF for structural health monitoring - Giorgio De Pasquale, Ferdinando Ursi (Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science, 2026)
Structural Health Monitoring (SHM) systems can rely on surface-mounted or embedded sensors; the latter approach protects against environmental exposure and enables placement within the host component, but is inherently constrained by manufacturing process compatibility. Fused Filament Fabrication (FFF) has emerged as a viable platform for embedded SHM, primarily through two strategies: Multi-Material Additive Manufacturing (MMAM) and Hybrid Additive Manufacturing (HAM). Despite growing interest, the effect of each embedding strategy on the structural integrity of the host component remains poorly quantified. This study addresses this gap through displacement transmissibility measurements on three FFF cantilever beam configurations: a Reference Beam (RB), a MMAM beam integrating a sensor based on Conductive Polymer Composite (MMAM-CPC), and a HAM beam with an embedded PZT piezoelectric sensor (HAM-PZT). Both MMAM-CPC and HAM-PZT sensors produce negligible stiffness changes. Resonance fr equency shifts are driven primarily by mass addition, significant only for the heavier PZT (+6.04%, −2.6% frequency reduction). Nonlinear dynamic behavior is evidenced by a decrease in resonance frequency and an increase in damping with excitation amplitude, a trend observed independently of the sensor used and attributed to the viscoelastic properties of the PLA matrix. The PZT sensor demonstrates superior sensing performance, with consistent sensitivity of 0.147 ± 0.001 V/g-pk and reliable broadband response ( R 2 > 0.980). The CPC sensor, which sensitivity of 5.201 ± 3.012 × 10 3 g-pk −1 , suffers from amplitude-dependency and irreversible resistance drift, raising concerns about its long-term operational reliability.

Magneto-Responsive Piezoelectric CoFe2O4-PVDF System for On-Demand Electrical Modulation of Infarcted Myocardium - Tao Jing, Yaolei Zhang, Zhongtao Li, Xiong Xiong, Hongyu Sun, Yonghong Fan, Chaoming Xie, Feng Lin (Materials Today Bio, 2026)
Myocardial infarction (MI) disrupts myocardial electrical conduction and contractile function, causing irreversible cardiac dysfunction. Piezoelectric materials offer great potential for MI repair via in situ electrical generation. However, traditional ultrasound-triggered piezoelectric activation inevitably induces local hyperthermia and secondary myocardial damage. Additionally, the piezoelectric therapeutic mechanisms for cardiac therapy remain poorly understood. Herein, we innovatively fabricated a magneto-responsive, self-powered CoFe 2 O 4 –PVDF composite therapeutic system. This composite achieves on-demand electrical modulation via non-invasive magnetic stimulation: CoFe 2 O 4 generates magnetostrictive strain under magnetic actuation, which is efficiently converted into functional piezoelectric charges by PVDF, thereby enabling safe, spatiotemporally controllable in situ cardiac electrical stimulation. In vivo results confirmed that the system significantly improved cardiac ej ection fraction and reduced myocardial fibrosis. It upregulated key genes governing angiogenesis, calcium signaling, and cardiomyocyte proliferation. In vitro, the composite promoted hypoxic H9c2 cardiomyocyte spreading and suppressed apoptosis under magnetic stimulation. First-principles calculations further verified that CoFe 2 O 4 optimizes the electronic state density of PVDF and enhances its charge output, revealing the synergistic mechanism. This work establishes an innovative magneto-driven, on-demand electrical therapy platform to overcome the limitations of conventional piezoelectric treatment. It provides novel mechanistic insights and a translational strategy for efficient MI repair via precise in situ regulation of the myocardial electrical microenvironment.

Enhanced Energy Harvesting Using Flexible PVDF/ZnO Nanosheet Composites for Piezoelectric Generator Applications - Nguyen Van Hung, Nguyen Duy Cuong, Nguyen Van Quy, Dong Quoc Viet, Tran Van Dang (VNU Journal of Science: Mathematics (Vietnam National University), 2026)
This study explores the piezoelectric properties of composite nanofilms composed of zinc oxide (ZnO) and polyvinylidene fluoride (PVDF) for application in piezoelectric nanogenerators (PENGs). By combining the high piezoelectric coefficient of ZnO with the mechanical flexibility and ferroelectric β-phase of PVDF, the composite aims to enhance mechanical-to-electrical energy conversion efficiency. The theoretical foundation is based on the piezoelectric behavior of ZnO’s non-centrosymmetric wurtzite crystal structure and the dipole alignment in PVDF. ZnO nanosheets were synthesized via a hydrothermal method and integrated into a PVDF matrix using spin coating to form dense, uniform composite films. Structural and morphological characteristics were examined using scanning electron microscopy (SEM), X-ray diffraction (XRD), and atomic force microscopy (AFM), while nanoscale piezoelectric performance was assessed through piezoresponse force microscopy (PFM). Under a mechanical load of 0.5 MPa at 1 Hz, the PVDF/ZnO-based PENG exhibited a peak output voltage of 10.5 V and a current density of 1.1 μA/cm², demonstrating stable and enhanced performance. These improvements are attributed to strong interfacial coupling and effective dipole orientation within the composite. This work presents a simple and scalable fabrication approach for high-performance, flexible PENGs, contributing to the development of compact, sustainable energy harvesting systems suitable for powering wearable electronics and other low-power devices.

Thermally Activated Piezoelectricity in PVDF-HFP/MWCNT Nanocomposites for Enhanced Energy Harvesting - Sawssan Jaballi, Ayda Bouhamed, Anouar Njeh, Olfa Kanoun (Polymer, 2026)

Synergistic improvement of piezoelectric and triboelectric responses in thermally exfoliated graphene oxide incorporated poly(vinylidene fluoride) nanocomposite - Siju Mishra, Hemraj Lakra, Kishore Hazarika, Nikhil Mohandas, Subrata Bandhu Ghosh, Sanchita Bandyopadhyay‐Ghosh, Arup R. Bhattacharyya (npj Flexible Electronics, 2026)
In this study, we have thoroughly investigated the intrinsic polarity-mediated optimization of multiple parameters, such as the piezoelectric coefficient, surface roughness, and surface work function, through the strategic incorporation of thermally exfoliated graphene oxide (TEGO) in poly(vinylidene fluoride) (PVDF) matrix, and its effect on piezoelectricity and triboelectricity. A higher density of delocalized π-electrons and oxygen-containing functional groups on the surface of TEGO regulated the electrostatic anchoring of -CH₂ dipoles in PVDF through π-dipole, dipole-dipole interaction to simultaneously induce a maximum polar phase content of ~89% at 2 wt.% TEGO concentration and a negative surface potential. This has resulted in a significant dual enhancement of charge generation and charge transfer through mechanical stimuli. The hybrid device yielded an instantaneous output power density of ~43.5 µW/cm², and a maximum external efficiency of ~42.4%, which was utilized to harvest various bio-mechanical energies, followed by the development of a smart health-monitoring system that calculates calories from footsteps in real time.

Influence Mechanism of KNN Particles with Varied Dimensionalities on the Ferroelectric and Piezoelectric Properties of PVDF-Based Composites - Haixuan Ren, Weimin Xia, Gaopeng Lv, Xusheng Wang (Polymer, 2026)

Fabrication of Sandwich-Structured Flexible Piezoelectric Sensors Using PVDF/BaTiO3 Composite Films Printed by Near-Field Electrohydrodynamic Direct-Writing - Jiaqi Wang, Huifang Liu, Xin Li, Fu Zhao, Luyao Zhao (Journal of Electronic Materials, 2026)

Development of a Piezo Biosensor for Pathogen-specific Biopolymer Detection Using Polymer Piezo Films: Investigation of Detection Characteristics of Piezo Biosensors and Self-assembled BaTiO3/Polymer Composite Materials - Mariko Takeda, Fumio Munakata (2026)
Infectious diseases are rapidly spreading across the globe. In this chapter, we propose a piezoelectric biosensor as an application of polymeric materials with dielectric properties. We emphasize the importance of combining isothermal genetic diagnostics with a piezoelectric biosensor that uses a piezoelectric polymer film, as it has significant potential for the early detection of infectious diseases. It is possible that piezoelectric biosensors using β-PVDF detect biopolymers through the relaxation behavior of β-PVDF. To solve the problems of β-PVDF, we developed self-assembled BaTiO3/polymer composite materials and applied the composite materials to the piezoelectric biosensors. The presence of a BaTiO3/polymer/BaTiO3 heterointerface within the self-assembled BaTiO3 aggregates forms an electric dipole, which plays an important role in improving the dielectric properties and piezoelectricity. It also leads to an improvement in the elastic constant. The piezoelectric biosensor using t he self-assembled BaTiO3/PVDF composite material has improved temperature characteristics.

Vacuum-Compatible Electrode-Free Poling of PVDF Films Using Glow-Discharge Plasma - B. A. Basov, Eugenia L. Buryanskaya, K. T. Makarova, Artur R. Zinnatullin, Konstantin Moiseev, А. С. Осипков, Alexander A. Maltsev, B. A. Parshin (Polymers, 2026)
Glow-discharge plasma (GDP) poling is revisited as an electrode-free method for activating piezoelectricity in poly(vinylidene fluoride) (PVDF) films. Although this method was proposed several decades ago, its effect on the properties of PVDF films has remained poorly understood. In this work, we demonstrate that GDP enables efficient poling of oriented PVDF films without pre-deposited electrodes and investigate the relationship between plasma treatment time, structural evolution, and piezoelectric response. Commercially available 25 μm-thick oriented PVDF films (PolyK) were treated in a DC glow discharge for 15 s to 15 min and characterized using FTIR, DSC, piezoresponse force microscopy, UV–Vis–NIR spectrophotometry, quasi-static d33 measurements and water contact-angle measurements. GDP poling produced a side-averaged piezoelectric coefficient d33 of up to ~25 pC/N within 1–5 min, with local maxima at approximately 1, 2.5, and 5 min. This behavior was accompanied by pronounced chang es in the domain structure, including an increase in the ferroelectric domain size from 86 to 552 nm, while the crystallinity and electroactive phase fraction changed only moderately. Plasma treatment also increased the wettability of the plasma-facing surface, reducing the water contact angle from about 85° to 42° within 3 min. At longer treatment times (>5 min), however, the piezoelectric response decreased and the optical transparency deteriorated because of increased haze and turbidity, most likely associated with plasma-induced chemical modification of the surface layers. These results indicate that GDP poling has an effective processing window of 1–5 min. The proposed approach provides a vacuum-compatible and electrode-free route for preparing PVDF films with increased surface wettability for flexible piezoelectric sensors, wearable electronics, and integrated polymer-based devices, because it is compatible with electrode deposition on an already activated polymer surface with in a single vacuum cycle.

High-Performance Piezoelectric Nanogenerators Based on Sol-Gel Synthesized BCZT Hybrid Nanocomposites - Sarra Missaoui (State and University Library Dresden (Saxon State Library), 2026)
Piezoelectric nanogenerators (PENGs) convert mechanical energy into electricity for self-powered wearable electronics. This thesis develops eco-friendly lead-free BCZT-MWCNT-PDMS nanocomposites for energy harvesting. BCZT was synthesized by the sol-gel method, enabling stoichiometric control and nanoscale particle formation. An optimized 15 wt.% BCZT composite generated a power density of 15.5 µW/cm³. Incorporating MWCNTs promoted conductive network formation, self-polarization, and dipole alignment without electrical poling. Optimized sonication improved filler dispersion, while 0.5 wt.% MWCNTs at the percolation threshold achieved 35.6 µW/cm³. The influence of calcination temperature (600-1000°C) on BCZT structural and piezoelectric properties was investigated. Calcination at 900°C produced crystalline nanoparticles with an average crystallite size of 18.16 nm and particle size of 68.9 nm. XRD and Raman analyses confirmed high crystallinity and a morphotropic phase boundary, enhancin g polarization rotation and domain wall mobility. The optimized BCZT-900/PDMS nanogenerator achieved 7.8 V and 29.5 µW/cm³ under cyclic loading with stable performance over 5000 cycles. Adding 0.5 wt.% MWCNTs increased performance to ±10 V and 53.2 µW/cm³. Monte Carlo Metropolis simulations confirmed the effect of calcination temperature on crystallinity and charge mobility. These results demonstrate scalable, performance PENGs fabricated through an environmentally friendly process.:Chapter 1. Introduction Chapter 2. Fundamentals of Dielectric and Functional Materials for Nanogenerators Chapter 3. Advances in BCZT-Based Functional Nanocomposites for Nanogenerators Chapter 4. Synthesis and Characterization Methodologies for BCZT-Based Nanocomposites Chapter 5. Investigation and Optimization of BCZT-MWCNT Hybrid Nanocomposites Chapter 6. Calcination Temperature Effects on BCZT Nanostructure and Energy Harvesting Chapter 7. Conclusion and Outlook

A Sustainable Chitosan‐MXene Engineered Nanogenerator With Enhanced Piezoelectric Output for Self‐Powered Wearable Systems - Snekaa Babu, Amirthavarshini Muthuraman, Loganathan Veeramuthu, Hemanth Jawaharlal, Yu-Syun Huang, Shih‐Yu Lin, Yu‐Wei Su, Chia‐Jung Cho (Advanced Materials Technologies, 2026)
ABSTRACT The rapid advancement of wearable electronics and self‐powered systems necessitates the development of flexible, sustainable, and multifunctional materials capable of efficient energy harvesting. In this study, a bio‐based piezoelectric nanogenerator is developed using a chitosan/poly (ethylene oxide) (PEO)/MXene (CPM) composite film. Chitosan provides intrinsic piezoelectricity and antibacterial activity due to its abundant functional groups, while PEO enhances flexibility and dipole mobility through hydrogen‐bonding interactions. The incorporation of multilayered MXene significantly improves interfacial polarization, mechanical strength, and charge transport within the composite matrix. The optimized CPM device exhibits a maximum output voltage of 16.43 V and a current of 0.62 µA under low‐frequency mechanical excitation. The device also demonstrates excellent durability, maintaining ∼88% performance after 8000 cycles. The CPM film exhibits superior recyclability and dual fu nctionality, maintaining approximately 92% of its original voltage after three successful recycling processes through reprocessing into new film, while also demonstrating excellent antibacterial properties. Additionally, the device effectively harvests biomechanical energy from human motions, enabling its application as a self‐powered sensing platform for wearable systems.

Recent Advances in Flexible Pressure Sensors: Mechanisms, Materials, Designs and Applications - Xiuzhen Yang, Chaojin Chen, Meng Wang, Kai Yao, Jiaoyue Zhang, Jiayi Lu, Ying Yi (Sensors, 2026)
In recent years, the rapid development of flexible electronics, smart materials, and micro/nanofabrication technologies has greatly promoted the advancement of flexible pressure sensors. These sensors have achieved significant improvements in sensitivity, detection range, stability, and functional integration, demonstrating great potential for applications in wearable electronics, smart healthcare, and human–machine interaction. This review summarizes recent progress in flexible pressure sensors in terms of sensing mechanisms, functional materials, structural designs, and intelligent applications. First, the working principles and performance characteristics of typical sensing mechanisms, including piezoresistive, capacitive, piezoelectric, triboelectric, iontronic, self-powered, and electrochemical sensing, are introduced and compared. Then, the development of key materials, such as flexible substrates, carbon-based nanomaterials, metal nanostructures, conductive hydrogels, and MXenes , is summarized. The effects of structural designs, including serpentine, three-dimensional porous, crack, wrinkle, and Kirigami structures, on flexibility, stretchability, sensitivity, detection range, and cycling stability are also discussed. Furthermore, the applications of flexible pressure sensors in pulse monitoring, blood pressure monitoring, human motion detection, cardiovascular health assessment, disease diagnosis, gesture recognition, human–machine interaction, and electronic skin are reviewed. Finally, the major challenges and future perspectives of flexible pressure sensors are discussed.

Candle soot-enhanced pyroelectric generator for thermal energy harvesting and self-powered sensing - Premkumar Bhosale, Sugato Hajra, Krystian Mistewicz, Mohamed Belal, Kushal Ruthvik Kaja, Basanta K. Panigrahi, Naratip Vittayakorn, Hoe Joon Kim (Carbon letters, 2026)
Abstract In recent years, there has been considerable interest in surface engineering using carbon-based coatings to improve pyroelectric performance. This work demonstrates a straightforward, economical method for a pyroelectric energy generator (PEG) using candle soot as a light-absorbing coating on a widely available PZT-based piezoelectric buzzer. Infrared (IR) lamp-induced thermal excitation was used to comprehensively assess the performance of the soot-coated and pristine PZT piezoelectric buzzer disk. Due to improved photothermal conversion, the coated PEG device exhibits a significant increase in electrical output. When exposed to the IR lamp, the short-circuit current reached approximately 204 nA, while the open-circuit voltage was approximately 4.8 V. Furthermore, under controlled thermal cycling, the device exhibited adjustable output and efficient energy storage. Further, the PEG was shown to be sensitive to temperature changes caused by human activity or the daily use of a ppliances, as well as to energy harvesting, suggesting its potential for self-powered sensing applications, such as breath monitoring, or converting energy from everyday appliances. Overall, this study presents a simple method to increase pyroelectric device performance efficiency in sensing and sustainable energy applications.

Synergistic Transdermal Drug Delivery via Piezoelectric P(VDF-TrFE)/Chitosan/Gold Nanohybrid Electrospun Membranes Combined with Targeted Ultrasonic Sonoporation - Shamo Salayev (Zenodo (CERN European Organization for Nuclear Research), 2026)
Transdermal administration of therapeutic ointments for cutaneous malignancies and severe localized bacterial infections is fundamentally constrained by the stratum corneum (SC) barrier. Here, we report a multi-modal transdermal drug delivery system comprising an electrospun piezoelectric Poly(vinylidene fluoride-trifluoroethylene)/Chitosan/Gold nanoparticle (P(VDF-TrFE)/CS/AuNP) membrane coupled with a custom-designed, multi-frequency ultrasonic excitation platform (1.0–3.0 MHz). The synthesized nanohybrid membrane exhibited superior biocompatibility, enhanced mechanical flexibility, and intrinsic acoustic impedance matching with human skin. FTIR and XRD analyses confirmed high 𝛽-phase crystallinity (82.4±1.8%) in the electrospun fibers, crucial for efficient electromechanical transduction. A custom dual-layer Printed Circuit Board (PCB) integrating an ATmega328P microcontroller and an AD9833 Direct Digital Synthesis (DDS) IC was fabricated to drive a PZT-5H ceramic transducer via an LC Butterworth impedance matching network. In vitro permeation tests using Franz diffusion cells demonstrated a 5.20±0.28-fold increase (𝑝<0.001, 𝑛=6) in the flux of a model oncology drug (5-Fluorouracil) across porcine skin under 2.4 MHz ultrasonic stimulation (1.2 W/cm2) compared to passive diffusion. Cytotoxicity assays (MTT) using L929 fibroblasts confirmed zero allergic response and 96.8±1.4% cell viability for the composite substrate. This integrative platform provides a non-invasive, highly controllable strategy for rapid local drug bio-absorption without systemic toxicity.

Enhanced piezoelectric performance of PVDF-based composite films prepared by tape casting for wearable sensor applications - Mozammal Haque, MD Kamrul Islam, Lei Xu, Ahmmed Jargige (Textile Research Journal, 2026)
Polyvinylidene fluoride (PVDF) is widely used in flexible sensors due to its excellent mechanical and piezoelectric properties. However, its performance is limited by low β -phase content and poor durability. This research optimizes PVDF-based piezoelectric films by incorporating binary and ternary copolymers, namely PVDF-trifluoroethylene and PVDF-trifluoroethylene-chlorotrifluoroethylene (PTC), using a tape casting and extrusion–calendaring process. A total of 18 blend compositions were evaluated, with a PVDF:PTC ratio of 1:1 identified as the optimal formulation, exhibiting the highest β -phase enhancement and improved ferroelectric response. Structural and electrical characterization was performed using Fourier transform infrared spectroscopy, X-ray diffraction, ferroelectric property testing, and impedance analyses, achieving values up to 250×10 −6 C N −1 . The optimized films demonstrated superior sensing performance, with high output voltage under dynamic finger tapping and stro ng linearity between the applied force and voltage response. Durability testing showed that the sensor retained >97% of its initial output after 8000 cycles and remained stable up to 11,100 loading cycles, indicating excellent mechanical robustness and long-term stability. Compared with pure PVDF, the optimized composite films exhibited significantly enhanced piezoelectric response, improved β -phase crystallinity, and better signal consistency. Finally, the films were successfully integrated into seamless wearable textiles for real-time motion sensing, demonstrating their applicability in smart sportswear. This study provides a scalable, effective approach to developing high-performance PVDF-based flexible sensors with enhanced efficiency, durability, and wearable compatibility.

Giant piezoelectric response and electromechanical coupling in AlScN thin films via multi-scale lattice engineering - Zhenyue Cheng, Zhenyue Cheng, Tong Liu, Daojian Su, Changhong Yang, Chuancheng Wu, Yao Liu, Wei Sun (Nature Communications, 2026)
High-performance AlScN thin films are critical for next-generation lead-free piezoelectric applications. Here, giant electromechanical coupling and piezoelectric response are demonstrated in Al0.9Sc0.1N thin films via a multi-scale lattice engineering strategy. Post-growth rapid thermal annealing significantly boosts the piezoelectric coefficient to 15.0 pC N−1 and electromechanical coupling to 34.9%. This performance enhancement stems from a synergistic mechanism: a reduced c/a lattice ratio and homogenized nanodomain alignment, fundamentally underpinned by a transition toward higher bond ionicity as evidenced by reduced minimum electron density at the bond saddle points. Leveraging an industrial-grade 6-inch wafer process, the prepared MEMS chip exhibits tailored electromechanical characteristics and a resonant frequency of 368.2 kHz. The optimized piezoelectric response enables record-breaking acoustic sensitivity of −162.4 dB at 10 Hz and a noise floor of 59 dB at 1 kHz, with robus t stability across diverse media and temperatures up to 150 °C. This work provides a scalable, mechanism-driven pathway for tailoring the electromechanical properties of AlScN thin films, addressing the long-standing challenge of high-fidelity weak signal detection in extreme environments. Multi-scale lattice engineering (reduced c/a, homogenized nanodomains, and enhanced ionicity) elevates AlScN films to a d33 of 15.0 pC N−1 and kt2 of 34.9%. Given this, the micro-electromechanical systems chip based on a 6-inch-wafer achieves a sensitivity of −162.4 dB.

Biodegradable 3D‐Printed Elastic Scaffolds With Bioactivity and Electro‐Mechanical Coupling Promote Neuro‐Vascularization for Critical‐Size Bone Defect Regeneration - Yuhao Xia, Yifu Zhu, Wenying Wei, Mengjiao Shi, Xiaopei Wu, Honglian Dai (Advanced Functional Materials, 2026)
ABSTRACT The intrinsic electrophysiological properties of native bone tissue promote bone healing, highlighting the significant role of piezoelectric biomaterials in neuro‐vascularized bone regeneration. However, challenges remain with existing piezoelectric biomaterials regarding biodegradability, bioactivity, and structural stability. In this study, a 3D‐printed elastic scaffold that uniquely integrates biodegradability, high bioactivity, and electro‐mechanical coupling was developed. The scaffold was fabricated by compounding piezoelectric whitlockite with an organic polymer matrix (polyvinyl alcohol/gelatin/sodium alginate). First, the mechanism underlying the enhancement of piezoelectric performance in whitlockite via annealing was elucidated, providing a theoretical foundation for optimizing the scaffold's piezoelectric properties. Next, through the design of a multi‐network composite ink system, stable dispersion and homogeneous compounding of whitlockite within the range of 20– 80 wt.% were achieved, along with high‐fidelity 3D printing of the scaffolds. Furthermore, precise modulation of the whitlockite loading ratio enabled synergistic optimization of the scaffold's piezoelectric responsiveness, mechanical adaptability, and biodegradation rate. In vitro and in vivo experiments collectively validated that the scaffold promotes neurogenesis, angiogenesis, and osteogenic differentiation through the synergistic interplay between electro‐mechanical coupling effects and the release of bioactive ions. This scaffold holds significant clinical potential for the regenerative repair of critical‐size bone defects.

A cylindrical three-dimensional rotary triboelectric nanogenerator with enhanced contact design for mechanical energy harvesting - Muhammad Mahdi Boroujli, Zohreh Golshan Bafghi, Milad Yousefizad, Pouya Paydari, Fatemeh Ahaninpajooh, Negin Manavizadeh, Alireza Khodayari, A. Moafi (Results in Engineering, 2026)
Rising interest in sustainable and self-powered electronic systems makes triboelectric nanogenerators a promising solution for harvesting ambient mechanical energy. This study proposes and investigates a cylindrical free-standing triboelectric nanogenerator (CF-TENG) to enhance energy conversion efficiency for self-powered systems. The device consists of a stator with interdigitated electrodes and a rotor with flexible blades coated by triboelectric materials. Performance was evaluated using different electrode materials (aluminum and polyamide-coated lacquered wire), triboelectric layers (Kapton and PTFE), and rotor blade configurations (double and quadruple) under various rotational speeds. The results show that both material selection and geometrical configuration strongly influence triboelectric output. PTFE outperforms Kapton in voltage and current generation due to its higher triboelectric charge density, while lacquered wire electrodes enhance charge generation compared to alumi num because of their higher electron affinity and enlarged effective contact area. The optimal configuration, consisting of quadruple PTFE-coated blades and lacquered wire electrodes, achieved 2086 V, 40 µA, and a peak power density of 5552.86 mW/m². Although increasing the blade number reduces rotational speed due to motor torque limits, it substantially improves energy harvesting. Capacitor charging tests confirm the capability of the proposed CF-TENG for efficient energy storage in practical low-power electronics.

Ultrahigh Contentβ-Phase and SuperiorPiezoelectric Output Performance of Poly(vinylidene fluoride)-BasedFlexible Composite Films Containing Low-Loaded MoS 2 /SnO 2 Heterostructured Nanofillers - Zhuo Sang, Shi Cao, Yuting Xu, Mengmeng Zhang, Tianyu Lu, Bin Yang, Jia Zhang, Feifan Zhao (Industrial & Engineering Chemistry Research, 2026)
Abstract Achieving a high β-phase content in poly(vinylidene fluoride) (PVDF) using low filler loadings remains a key challenge for flexible piezoelectric composites. Herein, a heterostructured MoS2/SnO2 nanofiller was designed to efficiently induce the nonpolar α-to-polar β-phase transition via interfacial charge transfer and built-in electric field effects. SnO2 nanoparticles were grown in situ onto the exfoliated MoS2 nanosheets to construct a 0D/2D heterojunction. At the interface, the work function difference drove charge transfer and interfacial polarization, which generated a strong built-in electric field, which synergistically promoted the alignment of PVDF’s-CF2-dipoles, in the presence of increased surface area and enhanced local stress transfer, thereby efficiently inducing the β-phase crystallization. PVDF/MoS2–SnO2 composite films containing 1.0 wt % heterostructured nanofiller were prepared by solution casting, and an optimal composite of PVDF/MoS2@SnO2 exhibited an ultr ahigh β-phase content of 80.2% (in comparison to a typical 10% for neat PVDF) as well as a fracture elongation above 15% (demonstrating its good flexibility). Under periodic pressure, it showed significantly enhanced electrical output: an open-circuit voltage of 5.92 V and a short-circuit current of 365.70 nA, which were averagely three times those of neat PVDF. The present work confirmed the efficacy of the MoS2/SnO2 heterostructure, which could provide a filler design strategy for high-performance, flexible piezoelectric composite films, highlighting their potential in sensing and energy harvesting.

Ag@BaTiO3 Core–Shell StructuredFillers Enabled P(VDF-TrFE) Composite Films for Self-Powered Pressureand Temperature Dual Mode Sensing - Jun Luo, Yuanyu Wang (Langmuir, 2026)
Abstract Flexible dual-mode pressure–temperature sensors face three key bottlenecks: low electrical conductivity, poor thermal conduction, and severe signal crosstalk. To overcome these challenges, we design Ag@BaTiO3 core–shell fillers embedded in a P(VDF-TrFE) matrix. The BaTiO3 core provides a stable dielectric response for temperature sensing, while the conductive Ag shell simultaneously enhances interfacial polarization, promotes β-phase nucleation, and improves thermal transport across the composite. The optimal formulation (15 wt % filler with 10 wt % Ag loading) yields a high β-phase content of 86.7% and a piezoelectric coefficient of 21.1 pC/N. The assembled piezoelectric nanogenerator delivers an open-circuit voltage of 29.25 V, a short-circuit current of 0.85 μA, and an output power of 25.1 μW, maintaining excellent stability over 4800 operating cycles. Moreover, the same film exhibits a temperature sensitivity of 0.8% °C–1 and a resolution of 0.1 °C. Notably, pressure and t emperature are transduced through independent physical channels─piezoelectric and capacitive, respectively. This core–shell strategy thus provides a scalable and efficient route toward self-powered, multifunctional sensors.

High-PerformanceAll-Textile Flexible PiezoelectricSensor Based on Electrospun MXene/PAN/K-BTO Nanofibers for WearableMotion Monitoring - Yexiong Qi, Zimeng Zhao, Li Chen, Ting-Ting Li, Ligang Lin, Zena Zhou, Yong Zheng (ACS Applied Nano Materials, 2026)
Abstract The all-textile piezoelectric sensor, capable of achieving high-sensitivity pressure sensing while meeting the requirements of wearability, comfort, and structural flexibility, holds great significance for intelligent wearable motion monitoring. In this study, MXene was employed to induce the transition of polyacrylonitrile (PAN) molecular chains from a 31 helical conformation to a planar zigzag conformation, which significantly enhanced the piezoelectric output performance. Under an impulse force of 7 N at 1 Hz, the sensor exhibited an output voltage of 34.1 V, with a sensitivity of 1.51 V/N over the range of 1–9 N. The silver-based knitted fabric electrode (silver-knitted fabric) was knitted on a computerized flat-knitting machine, fully leveraging the advantages of the knitted electrode, including high conductivity (resistance of only 4.2 Ω), high air permeability (1235 mm/s), and excellent structural flexibility. The electrospun MXene/PAN/K-BTO composite nanofiber membrane was subsequently integrated with the silver-based knitted fabric electrode to construct an all-textile flexible piezoelectric sensor with a three-layer sandwich structure. After 2000 consecutive impact cycles, the sensor output signal remained stable without any attenuation. The sensor accurately identified various human motion patterns, including finger bending (approximately 0.08 V), elbow flexion and extension, and walking gait (approximately 18.1 V). Owing to its excellent skin adherence and high sensitivity to subtle movements, this sensor provides an effective monitoring tool for intensive care and consciousness recovery assessment. Furthermore, it holds promising potential for applications in sports health monitoring and human–computer interaction, offering solutions for next-generation embodied intelligence and personalized health monitoring systems.

Strontium-ModifiedBaTiO3 Composite Nanogeneratorsfor Flexible and Self-Powered Human–Machine Interactions - Bojja Naveen Kumar, Kaliyannan Manojkumar, Thamil Selvi Velayutham, Suman Maloji, G. R. K. Prasad, Bhaskar Dudem, Venkateswaran Vivekananthan (ACS Omega, 2026)
Abstract Flexible piezoelectric nanogenerators (PENGs) have emerged as promising energy-harvesting devices for wearable electronics and self-powered human–machine interfaces. In this study, barium strontium titanate (BSRT) with varying Sr-substitution ratios was synthesized via a conventional solid-state reaction route, and its structural and functional properties were systematically evaluated. X-ray diffraction analysis confirmed the formation of phase-pure tetragonal perovskite BSRT and successful incorporation of Sr into the BaTiO3 lattice. The composition with 5% Sr exhibited optimized structural characteristics and was selected for device fabrication. Flexible BSRT-polydimethylsiloxane (PDMS) composite films were prepared and employed as the active layer in a sandwich-structured PENG. The electrical output performance was tuned by varying the filler loading, with an optimal composition of 15 wt % yielding a peak-to-peak voltage of 60 V and a short-circuit current of 5 μA under per iodic mechanical excitation. The device further demonstrated stable capacitor charging behavior, excellent mechanical durability, and the capability to power multiple light-emitting diodes. Additionally, a self-powered human–machine interface was demonstrated by integrating multiple PENG units with a microcontroller, enabling real-time slide navigation through simple finger tapping motions. This work highlights the potential of BSRT-based flexible PENGs as efficient energy harvesters and self-powered sensing platforms for next-generation wearable and interactive electronic systems.

A new approach to interfacial material effects on plane wave reflection–transmission in PZT-5A–epoxy composite structure - Bikram Dholey, Kshitish Ch. Mistri, G.C. Shit, Amrita Das, Koushik Maity (Journal of Vibration and Control, 2026)
This study introduces a new method on the reflection–transmission of obliquely incident quasi-Primary (qP) waves at an interface among two semi-infinite piezoelectric media, namely, a piezoelectric fiber-reinforced composite (PFRC) occupying the lower half-space and a homogeneous piezoelectric medium in the upper half-space. The two media are mechanically and electrically coupled through a common piezoelectric thin plate at the interface, modeled using the extended Gurtin–Murdoch surface elasticity framework. The angular dependence of all the reflected and transmitted waves follows a generalized Snell’s law, and energy flux analysis has confirmed near-conservation of total energy at the interface. Numerical computations demonstrate that interfacial stiffness, piezoelectric coupling, and PFRC volume fraction significantly influence wave reflection, transmission, and mode conversion. The results are relevant to the design and optimization of piezoelectric sensors, actuators, and energy h arvesting devices in smart composite structures and acoustic waveguides.

High-Performance Flexible Piezoresistive Sensors Based on Covalently Anchored Polypyrrole Networks on Electrospun Fibrous Membranes - Zhifei Liang, Fangrong Tan, Xinyu Zeng, Xiao Su, Zhe Tang, Paul D. Topham, Linge Wang, Qianqian Yu (Polymers, 2026)
Flexible piezoresistive sensors are highly desirable for wearable health monitoring, yet balancing ultrahigh sensitivity and wide pressure detection range is a major bottleneck restricting their applications in electronic skin and soft robots. This work constructs a hierarchical piezoresistive sensor through a simple three-step fabrication: electrospinning PVDF/PAN fiber networks, polydopamine (PDA) surface modification, and in situ polypyrrole (PPy) polymerization for conductive sensing layers. As a dual-function interlayer, PDA forms hydrogen and covalent bonds with PPy to yield uniform, firm conductive coatings. The link between PPy morphology and sensing performance is clarified by regulating polymerization parameters. At a pyrrole concentration of 3 g/L, the optimized sensor achieves a high sensitivity of 220.88 kPa−1 (0–10 kPa) and stable linear signals up to 1 MPa, with superior cycling durability over 5000 cycles and good biocompatibility. This scalable fabrication resolves the sensitivity–range tradeoff, promising wearable medical monitoring and human–machine interaction devices.

Frequency- and Path-Dependent Guided-Wave Sensitivity Assessment of an Aerospace-Type Sandwich Composite Floor Panel Under Bonded Patch-Induced Perturbations Using Piezoelectric Sensor Networks - YAŞAR KOYUTÜRK, Özkan Altay, Fu-Kuo Chang, Susheel Kumar Yadav, Serkan Kurt (Electronics, 2026)
Sandwich composite floor panels are widely used in aircraft interior structures because of their lightweight and high stiffness-to-weight characteristics. However, the guided-wave response of such panels is strongly influenced by their multilayer configuration, honeycomb core, attenuation behavior, sensor-path geometry, and excitation frequency. In this study, an active guided-wave-based Structural Health Monitoring (SHM) configuration was experimentally evaluated on an aerospace-type sandwich composite floor panel using a piezoelectric (PZT) sensor network. The specimen consisted of glass fiber reinforced polyetherimide (GFR-PEI) face sheets and a phenolic-coated aramid honeycomb core. Controlled bonded patch-induced surface perturbations were sequentially applied over 25 predefined panel regions to introduce repeatable local mass-loading and damping changes. Guided-wave measurements were performed using an Acellent ScanGenie system over a frequency range of 75–600 kHz with 25 kHz inc rements and twelve directed actuator–receiver paths. The results showed that the measured Damage Index (DI) response depends strongly on excitation frequency, sensing path, and perturbation location. The 400–450 kHz range produced relatively higher DI values under the tested configuration, and 425 kHz yielded the highest mean DI among valid measurements. However, the valid sensing coverage at 425 kHz was only 50%; therefore, this frequency was not interpreted as the most robust overall monitoring frequency. Lower frequencies around 100–150 kHz provided full sensing coverage while maintaining relatively high DI values. Frequencies above 550 kHz showed reduced measurement reliability due to increased attenuation and poor usable signal response. Overall, the study provides a comparative sensitivity assessment of a guided-wave-based PZT network on a sandwich composite floor panel under controlled bonded patch-induced perturbations, rather than a direct validation of realistic internal sand wich-panel damage mechanisms.