Chinese scientists develop "thermoelectric rubber"

On August 14, reporters learned from Qingdao University of Science and Technology that Professor Liu Kai of the university has developed the first N-type thermoelectric elastomer, also known as "thermoelectric rubber," offering a new solution for energy harvesting in flexible electronics and wearable devices. The research results were published in Nature on August 13.

Traditional thermoelectric devices have primarily used inorganic thermoelectric materials, which focus on applications in rigid structures and lack elasticity and shape adaptability, limiting their application in wearable devices. To address this issue, Liu Kai, leveraging the research results of Professor Lei Ting's team at Peking University and Professor Hua Jing's team at Qingdao University of Science and Technology, developed an N-type thermoelectric elastomer. This innovative material combines elasticity, stretchability, and thermoelectric conversion capabilities, opening up new directions in energy harvesting technology for wearable devices.

Liu Kai explained that he successfully synthesized the N-type thermoelectric elastomer by combining three strategies: uniform nanophase separation, thermally activated crosslinking, and targeted doping. The material exhibits excellent stretchability and resilience, with a tensile strain of up to 850%, comparable to traditional rubber. At the same time, its thermoelectric figure of merit reaches 0.49 at 300 Kelvin, approaching or even exceeding the performance of existing flexible or plastic inorganic thermoelectric materials.

By precisely selecting the combination of elastomer and dopant, the researchers not only improved the material's stretchability but also promoted the formation of uniformly distributed semiconducting polymer nanofibers, thereby increasing the material's electrical conductivity and reducing its thermal conductivity. This overcomes the limitations of thermoelectric materials in achieving both high performance and elastic tunability.

Based on this, the researchers fabricated the first elastic thermoelectric generator. Unlike inorganic thermoelectric devices, this elastic thermoelectric generator does not require complex interconnect structures and can conform directly to the skin surface while maintaining a high fill factor and low thermal resistance. The device combines high thermoelectric conversion efficiency with excellent comfort and shape adaptability, demonstrating potential for driving wearable electronic devices and biosensors.