Multifunctional Superelastic Graphene-Based Thermoelectric Sponges for Wearable and Thermal Management Devices

Power generation through harvesting human thermalenergy provides an ideal strategy for self-powered wearable design.However, existing thermoelectricfibers,films, and blocks have smallpower generation capacity and poorflexibility, which hinders thedevelopment of self-powered wearable electronics. Here, we report amultifunctional superelastic graphene-based thermoelectric (TE) spongefor wearable electronics and thermal management. The sponge has ahigh Seebeck coefficient of 49.2 mu V/K and a large compressive strain of98%. After 10 000 cyclic compressions at 30% strain, the sponge showsexcellent mechanical and TE stability. A wearable sponge array TEdevice was designed to drive medical equipment for monitoring physiological signals by harvesting human thermal energy.Furthermore, a 4x4 array TE device placed on the surface of a normal working Central Processing Unit (CPU) can generate astable voltage and reduce the CPU temperature by 8 K, providing a feasible strategy for simultaneous power generation and thermalmanagement.