KIST's Thermoelectric Generators Power Wearable Electronics From Your Body's Excess Heat

The Korea Institute of Science and Technology (KIST) has released a paper detailing a high-efficiency thermoelectric generator which it claims can be used to harvest power for wearable devices from simple body heat — and it's made by melting sugar.

Many designs for harvesting power for wearable electronics concentrate on absorbing energy from radio-frequency signals or the wearer's own movement. KIST's latest research, though, looks to use the wearer's body heat - and relies on a surprisingly simple new material to boost its efficiency to useful levels.

"The efficiency of our flexible thermoelectric device was raised to a level comparable to that of commercial thermoelectric devices through a simple, inexpensive process that requires pouring a solution on sugar and allowing the solution to solidify," explains Director Jin-Sang Kim of the team's work. "If we used a sufficient number of thermoelectric devices, it should certainly be possible to produce smart bands that operate on body heat alone."

To prove the concept, the team created a number of flexible thermoelectric models (TEMs) and noted a performance increase of 20 percent relative to a reference design using a traditional dense filler. These device were then used direct for powering electronics, with notable success. "Eight TEMs connected in series successfully operated 32 LEDs for more than 30 minutes when combined with a compact flexible heat sink," the paper's conclusion records.

"Apart from applying our approach as a power source for wearable electronics, the result of current study can influence various electronic devices requiring compact power sources or active temperature controls."

The team's work has been published under closed-access terms in the journal Nano Energy.