Development of Micro-Thermoelectric Generators for Powering Wearable Devices

In this work, we demonstrate and discuss the fabrication and performance of the micro thermoelectric generator (micro-TEG) for near room temperature on-body applications. A device size of 3.5 × 4.5 mm² is fabricated with two unique approaches: flip-chip bonding approach and suspended bridge device on a single silicon wafer. Both top and bottom gold (Au) interconnect, p-type CuSbTe and n-type Bi₂Te₃ thermoelectric materials are grown by the electrodeposition process. Flip-chip bonding delivers robust devices that can be directly used for the energy harvesting applications. This device, at a temperature gradient of 5 K and 10 K delivers a voltage output of 46 and 85 mV, respectively. A power density of 11.32 and 40.13 µW/cm² is achieved for those two temperature gradients. Thus, the micro-TEG developed in this work can offer a platform for providing electrical energy for wearable IoT devices.