Flexible thermoelectric generator with liquid metal interconnects and low thermal conductivity silicone filler
Viswanath Padmanabhan Ramesh, Yasaman Sargolzaeiaval, Taylor V. Neumann, Veena Misra, Daryoosh Vashaee, Michael D. Dickey, Mehmet C. Öztürk
Abstract
Abstract Harvesting body heat using thermoelectricity provides a promising path to realizing self-powered, wearable electronics that can achieve continuous, long-term, uninterrupted health monitoring. This paper reports a flexible thermoelectric generator (TEG) that provides efficient conversion of body heat to electrical energy. The device relies on a low thermal conductivity aerogel–silicone composite that secures and thermally isolates the individual semiconductor elements that are connected in series using stretchable eutectic gallium-indium (EGaIn) liquid metal interconnects. The composite consists of aerogel particulates mixed into polydimethylsiloxane (PDMS) providing as much as 50% reduction in the thermal conductivity of the silicone elastomer. Worn on the wrist, the flexible TEGs present output power density figures approaching 35 μWcm − 2 at an air velocity of 1.2 ms − 1 , equivalent to walking speed. The results suggest that these flexible TEGs can serve as the main energy source for low-power wearable electronics.