Thermoelectric generator with a high integration density for portable and wearable self-powered electronic devices

This work reports thermoelectric generators (TEGs) for portable and wearable self-powered electronic devices. Two kinds of TEGs, including low (device #1) and high (device #2) integrated number of thermoelectric elements, employing a high performance thermoelectric material fabricated by an assembly technology which are evaluated and compared against each other. Device #1 consists of 17 pairs of thermoelectric elements with dimensions of 1 mm x 1 mm x 2 mm while device #2 has 127 pairs of thermoelectric elements with dimensions of 0.4 mm x 0.4 mm x 2 mm. Both devices are fabricated on the same substrate of 15 mm x 15 mm. Maximum output powers for devices #1 and #2 are obtained as 10.1 mW and 33.9 mW at temperature difference Delta T of 75 degrees C, respectively, while at low.T = 5 degrees C, those of devices #1 and #2 are 43 mu W and 91 mu W, respectively. Fabricated TEGs show higher performance in comparison to the recent related works. Moreover, the harvested energy from the fabricated TEG can be stored in a rechargeable battery via a DC-DC converter. The output of the DC-DC converter reaches 2.8 V and 4 V at Delta T = 2 degrees C and 8 degrees C, respectively, which corresponds to the DC-DC electronic conversion efficiency.DC DC is 8.1% and 23.3%, respectively. The fabricated TEG as a power source for a calculator as well as a twist watch has been demonstrated successfully. The investigation in this work indicated that the fabricated TEG possesses a high potential for portable and wearable self-powered electronic devices.

Automated summary

This study presents thermoelectric generators (TEGs) for portable and wearable self-powered electronic devices, comparing two different devices with low and high numbers of thermoelectric elements. The TEGs demonstrate high performance and potential as power sources for portable and wearable electronic devices, with successful demonstrations as power supplies for a calculator and a twist watch. In addition, energy harvested from the TEGs can be stored in rechargeable batteries via DC-DC converters, with efficient electronic conversion.