Robust bendable thermoelectric generators enabled by elasticity strengthening

Using body heat for instance, thermoelectric generators have promising applications for driving wearable electronics continuously but remain a challenge in terms of recoverable flexibility, as known highly-performing thermoelectrics are usually inorganics showing rigidity. It is conceptualized in this work a large elastic strain ensuring both a largely-curved recoverable bending and a full recoverability in thermoelectric performance after enormous bendings. This leads the current work to focus on a microstructure engineering approach for strengthening the elasticity of Ag₂Se, in which dense dislocations and refined grain induced by a multi-pass hot-rolling technique enable a significant enhancement in elasticity. The resultant hot-rolled elastic thin thermoelectric generators realize a record bendability, for at least 1,000,000 times at a tiny bending radius of 3 mm with an extraordinary power density. Such a bendability is applicable to the most curved surfaces of a human body, suggesting a promising strategy for powerful wearable thermoelectrics of all inorganics.