Elastic Thermoelectric Generators Illustrated in Constantan

Functionalities of materials tightly relate to the atomic and electronic structures, the coupling between which through lattice and charge gives birth to thermoelectricity, enabling a direct heat-electricity conversion. Booming wearable electronics nowadays urgently demand thermoelectric film generators as self-powered units using body and environment heats, of which highly recoverable deformability and power are the core challenges. This indicates the great importance of elasticity since a plastic deformation otherwise actuates lattice slips to unsecure both thermoelectricity and recoverability. It is illustrated in this work texturization and dislocations for enhancing elasticity in cold-rolled constantan foils, a metal thermoelectric enabling one of the highest power outputs near room temperature for deformable wearables. The device can work in a purely elastic region, to secure orders of magnitude improvement in recoverable bendability with an extraordinary specific power density, at a bending radius down to 5 mm fitting the curvature of an adult's little finger. This work delivers a strategy for bringing robust deformability to thermoelectricity for powering wearable electronics.