Facile fabrication of stretchable and multifunctional thermoelectric composite fabrics with strain-enhanced self-powered sensing performance

Self-powered sensors have attracted extensive attention, which are farbicated based on thermoelectric materials that can operate in a self-powered mode. Their development faces challenges of limited preparation methods, complex structures and unstable sensing performance caused by the reduce of output signal during stretching. In this work, we prepared a thermoelectric composite fabric based on carbon nanotube (CNT)/polyvinyl pyrrolidone (PVP) by a facile ultrasonic coating method and further extended its application in self-powered temperature/strain sensing. PVP was used to disperse CNTs and increase the bonding force between fabric and CNTs, therefore maintaining stable thermoelectric properties under repeated bending and stretching. The presented self-powered temperature sensors show great potential in temperature recognition and breathing monitoring. Moreover, they additionally exhibits enhanced output signal upon stretching because of knitted fabric structure, which enables baseball players to optimize training behaviors. • Thermoelectric composite fabric exhibits excellent mechanical properties. • The sensor can realize self-powered sensing. • The sensor exhibits enhanced output signal when stretched.