Researchers from Ulsan National Institute of Science and Technology (UNIST) School of Materials Science and Engineering have developed a new wearable solar thermoelectric generator (W-STEG) in their recent study.
A thermoelectric generator harvests waste heat energy and converts it into electrical power. Its output is proportional to the square root of the temperature difference, and hence a large temperature difference is ideal for maximum energy production.
Whereas conventional thermoelectric generators using body heat had limited efficiency due to only a 1~4 oC temperature difference between the body and the surrounding environment, the UNIST researchers’ novel W-STEG is driven by an unprecedentedly high temperature difference of 20.9 oC. This breakthrough was achieved through integration of thick sub-micron solar absorbers on a polyimide substrate, yielding an open-circuit voltage of 55.15 mV and an output power of 4.44 μW upon sunlight exposure.
The new W-STEG is expected to enhance commercialization of thermoelectric generators and further expand the wearable electronic technology market.