Wearable thermal energy harvester powered by human foot

With explosive applications of many advanced mobile electronic devices, a pervasive energy system with long term sustainability becomes increasingly important. Among the many efforts ever tried, human power is rather unique due to its independence of weather or geographical conditions and is therefore becoming a research focus. This paper is dedicated to demonstrate the possibility and feasibility of harvesting thermal energy from human body by sandwiching a thermoelectric generator (TEG) between human shoe bottom and ground, aiming to power a portable electronic device. Through the conceptual experiments conducted on adults, a maximum 3.99mW steady state power output at a ground temperature with 273 K is obtained, which is sufficient enough to drive a lot of microelectronic devices. Also, parametric simulations are performed to systematically clarify the factors influencing the TEG working performance. To further reveal the mechanism of this power generation modality, analytical solutions to the coupled temperature distributions for human foot and TEG module are obtained and the correlation between TEG characteristics and the output power are studied. It was demonstrated that, the TEG working as a wearable power resource by utilizing thermal energy of human foot shows enormous potential and practical values either under normal or extreme conditions.