Review on Fiber-Based Thermoelectrics: Materials, Devices, and Textiles

With the development and prosperity of Internet of Things (IoT) technology, wearable electronics have brought fresh changes to our lives. The demands for low power consumption and mini-type wearable power systems for wearable electronics are more urgent than ever. Thermoelectric materials can efficiently convert the temperature difference between body and environment into electrical energy without the need for mechanical components, making them one of the ideal candidates for wearable power systems. In recent years, a variety of high-performance thermoelectric materials and processes for the preparation of large-scale single-fiber devices have emerged, driving the application of flexible fiber-based thermoelectric generators. By weaving thermoelectric fibers into a textile that conforms to human skin, it can achieve stable operation for long periods even when the human body is in motion. In this review, the complete process from thermoelectric materials to single-fiber/yarn devices to thermoelectric textiles is introduced comprehensively. Strategies for enhancing thermoelectric performance, processing techniques for fiber devices, and the wide applications of thermoelectric textiles are summarized. In addition, the challenges of ductile thermoelectric materials, system integration, and specifications are discussed, and the relevant developments in this field are prospected.