A team of Korean researchers has developed a new thermoelectric material designed for wearable devices like smart clothing or medical sensors. It can generate stable thermal energy even in extreme conditions, balancing thermoelectric material performance with flexibility. The breakthrough also looks promising for commercialization.
Led by KAIST Professors Yeon Sik Jung and Inkyu Park, along with collaborators from Hanbat National University and the Korea Institute of Machinery and Materials, the research team created a flexible “bismuth telluride (Bi2Te3) thermoelectric fiber.” The fiber is also an innovative solution for energy harvesting in next-generation electronics, especially for wearable applications.
Thermoelectric materials work by converting heat differences into electrical energy. Currently, 70% of that energy is wasted as heat. We can also use this technology to turn waste heat on curved heat sources like human bodies and vehicle exhausts into energy.
Traditional ceramic-based thermoelectric materials offer high performance but are too brittle for flexible applications. Conversely, flexible materials with polymer binders have limited conductivity, reducing efficiency.
The team addressed both issues by twisting nanoribbons into a thread-like structure, eliminating the need for polymers and maintaining high flexibility and conductivity. Using a unique electron beam deposition technique, they created robust, all-inorganic thermoelectric fibers with excellent durability, withstanding over 1,000 bends without performance loss. These traits make them ideal for applications that require durability and flexibility, like wearable devices. This means that clothes made of these fibers could harvest body heat to generate electricity for other electronic devices. It also opens the possibility of efficiently recycling waste heat in industrial settings (the heat difference between a hot fluid pipe and the air outside, for example) on a commercial level.
