An NSF sponsored nanoengineering research center, ASSIST or Advanced Self Powered Systems of Integrated Sensors of North Carolina State University, have been developing sensors that use body heat to power up wearable gadgets.
The sensor is made of Thermoelectric material and operates in the concept of thermoelectric effect, also called as the Peltier-Seebeck Effect, a direct reversible conversion of temperature difference to voltage with the use of two dissimilar metal junctions.
The idea behind this wonderful technology is that it operates on temperature difference, between the skin and the ambient air. For a 3 degree centigrade difference, the said device could produce about 40 to 50 microwatts per square centimeter with no heat sink or air flow on it.
Though, at 40 to 50 microwatts per square centimeter, it might not be enough to power a GPS or any bigger gadgets than that, but for gizmos such as low-powered vital health sensors like temperature, pressure and hydration transducers, it certainly is capable.
This power generating device works great, especially when wearing it during extraneous activities like workouts and other sporty events, or when surrounding temperature drops in the evening or in the winter. But, its developed power is drastically lowered when ambient temperature is close to body temperature.
The future market of this thing may not be suitable to warmer regions of the planet like the Middle East, but is still pretty interesting to see its principle of operation.
The researchers at ASSIST are refining the device’s material without sacrificing durability and flexibility of the product and they are into the point where they can reliably make dozens or hundreds of it. The team is now looking for an industry partner who can help release the product to the market.