Design, Fabrication and Characterization of a Vibration Driven Multi-frequency Electromagnetic Energy Harvester

This paper presents design, fabrication and characterization of an electromagnetic energy harvester, which can operate at different resonance frequencies. It utilizes magnetic spring technique to scavenge energy from low frequency vibrations. The optimization of generator is done in two stages. First, optimization of a single harvester is done in terms of number of turns, coil width, coil position and spacing between the fixed magnets. Second, a transducer composed of four generators is designed for different combination of moving and fixed magnets and hence, the device can operate at different natural frequencies. The device generates a power of 1.662.82 mW for an external vibration of 7-10 Hz frequency range with 0.5g acceleration.