Several surveys suggest that limited battery capacity is a barrier to wider adoption of wearables in sports and health/fitness industry. The consumers either tend to forget charging their devices or they deprioritise wearable over other important gadgets like mobile phones.

This could change as researchers at North Carolina State University have developed a prototype that harvest body heat and convert it into electricity to use in wearable electronics.  This has been tried and implemented before but the previous technology used heat sinks making it heavy, stiff in bulky.

This new technology called Wearable thermoelectric generators (TEGs) are lightweight, comfortable and efficient.

The new design begins with a layer of thermally conductive material that rests on the skin and spreads out the heat. The conductive material is topped with a polymer layer that prevents the heat from dissipating through to the outside air. This forces the body heat to pass through a centrally-located TEG that is one cm2. Heat that is not converted into electricity passes through the TEG into an outer layer of thermally conductive material, which rapidly dissipates the heat. The entire system is thin – only 2 millimeters – and flexible.

The prototype design is only one centimeter in size though the researchers believe it can easily be made bigger depending on the power need. The researchers also incorporated the TEG into T-shirts and while running, it can generate 16 µW/cm2. T-shirt is not the only choice of TEG position. The researchers believe the best option is upper arm bands.

To read more about the research or to read the journal, you can visit the Science Direct website.