Highly stretchable, durable, and breathable thermoelectric fabrics for human body energy harvesting and sensing

Abstract Stretchable thermoelectrics have recently attracted widespread attention in the field of self‐powered wearable electronics due to their unique capability of harvesting body heat. However, it remains challenging to develop thermoelectric materials with excellent stretchability, durable thermoelectric properties, wearable comfort, and multifunctional sensing properties simultaneously. Herein, an advanced preparation strategy combining electrospinning and spraying technology is proposed to prepare carbon nanotube (CNT)/polyvinyl pyrrolidone (PVP)/polyurethane (PU) composite thermoelectric fabrics that have high air permeability and stretchability (~250%) close to those of pure PU nanofiber fabrics. Furthermore, PVP can not only improve the dispersion of CNTs but also act as interfacial binders between the CNT and the elastic PU skeleton. Consequently, both the electrical conductivity and the Seebeck coefficient remain unchanged even after bending 1000 times. In addition, self‐powered sensors for the mutual conversion of finger temperature and language and detection of the movement of joints to optimize an athlete's movement state were successfully fabricated. This study paves the way for stretchable thermoelectric fabrics with fascinating applications in smart wearable fields such as power generation, health monitoring, and human–computer interaction.