Flexible thermoelectric power generators based on electrochemical deposition process of BI₂TE₃ and SB₂TE₃

The harvest of thermal energy using thermoelectric (TE) effect is one of the potential methods for wearable devices. This paper demonstrates a new approach of electrochemical deposition to fabricate flexible thermoelectric generators (FTEGs). Two proposed structures have been developed to compare the performance of the devices. One is the π-type flexible devices with thick thermoelectric cells in micro scale and the other is a new lateral Y-type structure for FTEGs. For the first time, the electrochemical deposition of thermoelectric materials Bi₂Te₃ and Sb₂Te₃ is used to integrate thermoelectric materials inside the flexible structures. The Seebeck coefficients of Bi₂Te₃ and Sb₂Te₃ are -150±20 and 170±20 μν/Κ, respectively. Additionally, the electrical resistivity of Bi₂Te₃ shows 15±5 μΩm while that of Sb₂Te₃ is 25±5 μΩm. The thicknesses of each thermocouple (TCs) are approximately 100 μm and 200 μm for Y-type and π-type, respectively. With the temperature difference approximately 22°C between human body (around 37°C) and environment ambience (15°C), the lateral Y-type and vertical π-type devices generate maximum powers approximately 3 and 4 μW/cm², respectively.