A miniature, thin-film thermoelectric generator from Nextreme, Research Triangle Park, N.C., turns heat into electricity using what is called the Seebeck Effect.
A temperature differential applied across the device changes its Fermi energy, creating an electrical potential.
Standard semiconductor fabrication methods build the 3.5-mm-sq solid-state generators. Power density is >3 W/cm2 at a ΔT = 120°C, higher than that of bulk materials and about 1/20th the thickness. Target markets and applications include automotive, military and aerospace, thermal batteries, medical implants and wireless sensor networks.