Flexible thermoelectric generators can directly convert low-grade thermal energy available in daily life into electricity, offering a promising power-supply strategy for next-generation wearable electronics.
A research team from Tianjin University, Fujian University of Technology, and Fuzhou University has developed high-performance flexible thermoelectric generators based on Bi 2 Te 3 /hydroxypropyl methylcellulose (HPMC)@paper composite films. This work was published in Nano Research on July 7, 2026. A central challenge for flexible thermoelectric devices is how to simultaneously achieve high energy conversion performance, mechanical flexibility, and stable output under repeated deformation. Conventional inorganic thermoelectric materials generally exhibit favorable thermoelectric properties; however, their inherent rigidity and brittleness make them difficult to integrate effectively with curved, soft, and dynamically moving human-body surfaces. Existing flexible thermoelectric generators also commonly suffer from inefficient heat collection, limited output power, and unstable electrical performance during bending.
To address these challenges, the research team fabricated Bi 2 Te 3 /HPMC@paper composite thermoelectric films using a vacuum filtration method. In this design, Bi 2 Te 3 -based thermoelectric particles serve as the primary energy-conversion component, while the HPMC network and paper-based structure enhance the flexibility, interfacial adhesion, and mechanical stability of the films. The resulting p-type and n-type composite films achieved Seebeck coefficients of 182.96 and −229.98 μV·K -1 , respectively, while maintaining stable output under repeated bending.
According to the authors, integrating inorganic thermoelectric materials with a flexible polymer–paper framework helps overcome the long-standing trade-off between thermoelectric performance and mechanical adaptability, providing a robust platform for flexible thermoelectric devices that can operate on curved and moving surfaces.
Based on these composite films, the researchers further designed flexible thermoelectric generators with both planar and multilayer-stacked architectures. The planar configuration enables compact integration of multiple p–n thermoelectric units, whereas the stacked architecture improves the utilization of vertical temperature gradients, which is particularly important for harvesting heat from skin and other nonplanar heat sources. The Level-III multilayer-stacked flexible thermoelectric generator exhibited a device-level Seebeck coefficient of 11,330.25 μV·K -1 and a maximum output power of 617.4 nW, demonstrating excellent energy conversion capability and structural robustness. After integration with an Ecoflex flexible substrate, the device maintained stable operation under bending, twisting, and conformal attachment to curved surfaces.
To further demonstrate its practical potential, the team constructed a smart wristband based on the flexible thermoelectric system. When worn on the human wrist, the device harvested body-surface heat and generated thermoelectric signals, which could continuously drive a low-power pedometer after voltage amplification. This demonstration validates the feasibility of the device for wearable thermoelectric energy harvesting.
The key message of this work is that material flexibility and device-level output can be simultaneously enhanced by combining inorganic–organic hybrid films with hierarchical device architectures. Rather than treating material design and device architecture as separate issues, this study integrates them into a unified design pathway toward wearable energy systems. Looking ahead, the research team believes that further optimization of thermoelectric materials, device geometry, encapsulation strategies, and power-management circuits could improve output power and long-term reliability under real wearing conditions. Potential applications include wearable health monitoring, low-power sensors, electronic skins, and distributed body-heat energy harvesting systems.
About the Authors
Hechen Ren is a tenured professor under the Peiyang Young Scholars Program and a doctoral supervisor at the Center for Joint Quantum Studies, School of Science, Tianjin University. His research primarily focuses on experimental condensed matter physics and topological quantum computation, including the investigation of low-dimensional quantum systems with topological properties at low temperatures and the development of next-generation quantum devices for topological quantum computing. His group employs experimental techniques such as quantum transport, phase control, and quantum tunneling to characterize and optimize topological superconducting devices. His research interests also include nanofabrication based on quantum materials and spintronic devices.
Qiaohang Guo is an associate professor at the School of Materials Science and Engineering, Fujian University of Technology. His research interests include the preparation and application of metallic thin films, microscale sensing devices, self-driven deformation materials, biomimetic functional materials, and nanotriboelectric generators. His work mainly focuses on the design and application of flexible functional materials, micro/nano sensors, self-powered devices, and biomimetic intelligent systems.
Mingcen Weng is a research professor at the Institute of Biology and Chemistry, Fujian University of Technology. His team is mainly engaged in the preparation and application of intelligent actuating materials, with a particular focus on the stimulus-responsive mechanisms, deformation regulation mechanisms, and multifunctional integration of flexible actuating materials.
DOI Link:
https://doi.org/10.26599/NR.2026.94908713
About Nano Research
Nano Research is a peer-reviewed, open access, international and interdisciplinary research journal, sponsored by Tsinghua University and the Chinese Chemical Society, published by Tsinghua University Press on the platform SciOpen. It publishes original high-quality research and significant review articles on all aspects of nanoscience and nanotechnology, ranging from basic aspects of the science of nanoscale materials to practical applications of such materials. After 18 years of development, it has become one of the most influential academic journals in the nano field. Nano Research has published more than 1,000 papers every year from 2022, with its cumulative count surpassing 8,000 articles. In 2025 InCites Journal Citation Reports, its 2025 IF is 9.4 (8.3, 5 years), and it continues to be the Q1 area among the four subject classifications. Nano Research Award, established by Nano Research together with TUP and Springer Nature in 2013, and Nano Research Young Innovators (NR45) Awards, established by Nano Research in 2018, have become international academic awards with global influence.
Nano Research
High-performance flexible thermoelectric generators with planar and multilayer-stacked structures for wearable electronics
7-Jul-2026