Design and Fabrication of a Mems Thermoelectric Generator for Energy Harvesting

This paper presents a technology platform to fabricate micro thermoelectric generators (μTEG) with thin-film thermopiles. The combination of bulk and surface micromachining processes allows the integration of in-plane thin-film thermopiles in a device with a cross-plane heat flux. Heat flux guiding structures are used to maximize the temperature difference across the thermopiles. FEM simulations indicate that up to 94% of the total temperature difference applied across the generator chip is located between the thermocouple junctions. A demonstrator device and test structures are manufactured using ntype poly-Si and Al as active materials. Measurements show a linear output voltage of 76.08 μVK per thermocouple which would result in a device power factor of 1.612·10 4 μWmmK.