A disruptive technology for thermal to electrical energy conversion

A disruptive approach to thermal energy harvesting is presented. The new technique can be used for powering ultra-low power electronics and autonomous systems. We propose a two step conversion of heat into electricity: thermal to mechanical and mechanical to electrical. Devices can work in a wide range of temperatures: from -40°C to 300°C, and the available mechanical power density is in the order of 1 mW/cm
²
. We evidenced that one of the keys to improve the generated power density is downscaling of individual devices. To demonstrate this point, laws modeling downscaling have been established and show that the miniaturization of the devices by a factor k increases the generated power density by the same factor, thanks to the higher speed of heat transfer.