Thermoelectric Matrix for Human Warmth Harvesting as Secondary Energy Source in Wearable Electronics

The paper deals with an idea of a thermoelectric matrix which is capable of harvesting free available energy dissipated in a form of human heat. The main objective of the work was to provide a proof of concept that the human warmth converted into electrical energy can be used as a secondary power source supporting primary battery in a sensor bracelet. The scope of the article includes presentation of the thermoelectric matrix structure and its electrothermal model in a few configurations of mini-TEGs outputs connections. Then a set of results is presented showing coupled electrical and thermal experimental simulations of the harvesting matrix connected to an ultra-low voltage converter LTC3108. The obtained characteristics of the equivalent output Seebeck voltages and available electrical power in respect to the mini-TEGs connections configurations indicate the best scenario in terms of energy conversion efficiency.