KAIST TE generatorWearable technology has wonderful potential, especially for health and fitness applications. But there is one important problem that must be solved; how are you going to power these devices? One common solution is to use batteries, but these must be recharged if possible, and eventually replaced. Designers are constantly searching for ways to harvest energy from the user’s environment to either recharge batteries or provide a power source without the need for energy storage at all.

Researchers at the Korea Advanced Institute of Science and Technology (KAIST) have come up with a possible solution. They have developed a highly efficient, flexible thermoelectric (TE) generator that creates electricity using the difference in temperature between the user’s skin and the ambient air. To date, polymer-based organic TE devices have been flexible but inefficient. Inorganic TE devices are more efficient, but have required rigid substrates. The KAIST researchers have developed a way to screen print inorganic materials on woven glass cloth, resulting in an efficient and flexible device that can produce about 40 mW of power based on a 31 degree F temperature differential between the user’s skin and the air.

The KAIST researchers published their results in Energy & Environmental Science, Issue 6, 2014.