High-Power-Density\nWearable Thermoelectric Generators\nfor Human Body Heat Harvesting

Abstract

Wearable thermoelectrics has attracted\nsignificant interest in\nrecent years. Among them, rigid-structure thermoelectric generators\n(TEGs) were seldomly employed for wearable applications, although\nthose exhibit significant advantages of high device output performance\nand impact resistance. Here, we report a type of rigid wearable TEGs\n(w-TEGs) without ceramic substrates made using a simple cutting-and-bonding\nmethod. Owing to the small contact area, the w-TEGs comprising 48-n/p-pairs\ncan be well attached to the human body. The lack of ceramic substrates\nleaves more space in the height direction, which benefits the wearability\nin practical applications and high power density. We demonstrated\nthat increasing the height of w-TEGs from 1.38 to 3.14 mm significantly\nimproves the power density by a factor of 10. As a result, the maximum\npower densities of 7.9 μW cm^–2 and 43.6 μW\ncm^–2 for the w-TEGs were realized under the breezeless\ncondition and a wind speed for normal walking, respectively. This\nwork provides a feasible design solution for rigid-structure free-substrate\nw-TEGs with very high power density, which will speed up the research\nof wearable thermoelectrics.