High-performance flexible thermoelectric devices with a copper foam heatsink for personal thermal management

Abstract

A flexible thermoelectric device (F-TED) possesses two distinct advantages: harvesting residual heat from the human body to power electronic devices and regulating body temperature to achieve thermal comfort states. These unique merits have sparked widespread research into their application in personal thermal management (PTM). However, inorganic and thin-film TEDs suffer from drawbacks such as limited power output and complex fabrication processes. Here, we have developed a foldable, high-performance F-TED based on bismuth telluride with polyimide as the substrate and polydimethylsiloxane as the encapsulation material. The F-TED demonstrates an open-circuit voltage of up to 404 mV, an output power of 80 mW, and a power density of 9 mW cm⁻² at ΔT = 50 K, respectively. In further PTM experiments, the copper foam is employed as a heatsink to effectively maintain the F-TED temperature difference. The modified F-TED exhibits a consistently increased output power of over 40% across different air velocities compared to the F-TED without the heatsink, and it also realizes stable skin temperatures during skin cooling, demonstrating significant potential for application in PTM.