Durable, stretchable and washable inorganic-based woven thermoelectric textiles for power generation and solid-state cooling

Abstract

Wearable inorganic semiconductor (ISC) based thermoelectric (TE) devices, especially fiber-based thermoelectric textiles (TETs), show promise in electrical power generation and solid-state cooling compared with bulk ISC-based TE generators (TEGs). However, it is challenging to use the ISCs, with brittleness and mechanical instability, to produce thermoelectric fibers for weaving TETs. Here, we report a strategy to produce ISC-based segmented hierarchically ternary coaxial TE strings at large scale for semi-automatically manufacturing a highly mechanically stable, stretchable, breathable and washable woven TET by a textile machine. The TET demonstrates good stretchability (100% elongation), flexibility (bending radius of 2 mm), washability (>20 washing cycles) and output power density of 0.58 W m⁻² at a temperature difference of 25 K (predicted power density of 6.06 W m⁻² at ΔT = 80 K). With the assistance of finite element analysis, the significance of the fabric’s structure on the excellent mechanical and TE performance of the TET has been clarified, which reaches an output voltage of ∼0.28 V at an ambient temperature of ∼8 °C. For practical applications, it can continuously power on-body electronics for monitoring the environment and the human body’s vital signals and activities by wearing it on the arm with a self-built temperature gradient of ∼16 K. Furthermore, the TET can stably generate solid-state cooling of 3.1 K in quiescent air (T_ambient ∼ 26 °C, relative humidity ∼60%). This work paves a new way for designing durable, stretchable and washable ISC-based TETs toward real on-body applications.