Revolution in Charging Technology
A Korean research team has developed a new technology to power wearable devices with body temperature, with wearable devices emerging as a next-gen platform following smartphones.
The Korea Advanced Institute of Science and Technology (KAIST) announced on April 7 that a research team led by Cho Byung-jin, professor of the Division of Electrical Engineering at KAIST, succeeded in developing a new method to make a new thermoelectric module that can convert body heat into electricity using glass fabric.
The research team grounded n-type (Bi2Fe3) and p-type (Sb2Te3) materials into power, and mixed the powdered materials and a special solvent to make a thick paste. Finally, the paste was screen-printed onto a glass fabric as dots 1.5 mm in diameter and approximately 500 µm thick. The result was a thermoelectric module for a wearable device, which is 14 times as efficient as traditional ceramic substrates in producing electricity, and lighter too.
A 10×10 cm band-shaped device attachable to a human arm may produce around 40 milliwatts of electricity at 20 degrees Celsius, enough to power a semiconductor chip. In particular, a 50×100 cm device attached to the torso can generate 2W of electricity, which is enough to fully charge a cell phone.
Professor Cho explained, “The biggest obstacle to the commercialization of wearable devices is related to problems with power supplies. So, a battery of any wearable device is required to be frequently replaced at the moment. And the battery itself is heavy. However, it is now possible to utilize wearable devices semi-permanently using this thermoelectric module, because it generates electricity with body temperature.” He added, “Unlike the conventional organic-based thermoelectric module, the newly-developed one can be made on a large scale. Furthermore, it can also be utilized in converting waste heat coming out of cars, factories, airplanes, and ships into electricity.”
This study was funded by the Ministry of Science, ICT and Future Planning, and the research findings were first published online on March 14 by Energy & Environmental Science, a monthly scientific journal.