A flexible heat harvesting device shows better efficiency at retaining heat to power the device. (Credit: Mehmet Ozturk)

Researchers report significant enhancements in preventing heat leakage in the flexible body heat harvester. The harvesters use heat energy from the human body to power wearable technologies such as smart watches that measure heart rate, blood oxygen, glucose, and other health parameters and never need to have their batteries recharged. The technology relies on the same principles governing rigid thermoelectric harvesters that convert heat to electrical energy.

Improvements to the device in 2020 included a high thermal conductivity silicone elastomer — essentially a type of rubber — that encapsulated the EGaIn interconnects. The newest iteration of the device adds aerogel flakes to the silicone elastomer to reduce the elastomer’s thermal conductivity. Experimental results showed that this innovation reduced the heat leakage through the elastomer by half.

One the patented technology’s strengths is that it employs the same semiconductor elements that are used in rigid devices perfected after decades of research. The approach also provides a low-cost opportunity for existing rigid thermoelectric module manufacturers to enter the flexible thermoelectric market.

For more information, visit here .