A millimeter-scale electric generator

The research presented in this paper concerns the design, construction and testing of an electrical generator intended for interface with a MEMS internal combustion (IC) Wankel engine. The engine and generator are integrated into a single unit by utilizing the engine rotor as the generator rotor. The design allows for thermal insulation between the stator and combustion chamber, simple assembly of the engine and generator and excellent utilization of copper in the generator winding. The majority of the generator structure is built from discrete millimeter-scale components, with only the rotor being microfabricated. Prototype construction and testing are described; a peak open-circuit voltage of 2.63 V and a maximum power output of 375 muW at 13.3 kRPM are reported.