Energy Harvesting for Electronics with Thermoelectric Devices using Nanoscale Materials

Significant developments have occurred in the last few years in the area of nanoscale thermoelectric materials using superlattices and self-assembled quantum-dots. Thin-film thermoelectric (TE) devices employing these materials have been developed for many applications including energy harvesting. Thin-film TE devices, for a 1 mm³ of converter volume, are available that can produce well over 775 muW/mm3 with an external DeltaT of 9 K. Such modules can be packaged within conventional chip packages, unobtrusively, and provide valuable DC electric power in the range of 100 mW without the need for any DC-DC conversion using heat produced by ~10 to 20 Watt chips. Even larger power levels are harvestable in high power electronics such as IGBTs. It appears that the advanced TE modules can provide sufficient power, over the background requirements, to directly power electronics with temperature differentials as little as 1degC. Near-term candidate applications are in bio-implants, sensors, robotics and energy-limited electronics in thermally active environments. Miniature thermoelectric power harvesters can be integrated with other energy harvesting technologies such as photovoltaics and vibration energy harvesters to provide universal energy harvesting for autonomous systems.