Broadband MEMS energy harvester with monolithically integrated NdFeB magnets

Abstract:
MEMS-based energy harvesting is a potential efficient, miniaturized power source for autonomous sensor nodes. However, low power output, specifically for low excitation frequencies, limits the application range. Here a novel fabrication technique was facilitated to integrate micrometre-sized magnets on wafer-level allowing to harvest alternating magnetic fields and mechanical vibrations. Frequency up-conversion by magnetic plucking allows to harvest from varying and low-frequency excitations. Considering resonant excitation by external permanent magnets, RMS power outputs >120 muW are achieved. Furthermore, first results demonstrate that the power output via integration of AlScN can be significantly increased by a factor of ≈ 2.