Design and prototyping of second generation METU MEMS electromagnetic micro-power generators

This paper presents an electromagnetic (EM) vibration to electrical power generator which can effectively harvest energy from low frequency external vibrations. The reported second generation MEMS energy scavenger module up-converts low frequency environmental vibrations before mechanical-to-electrical conversion. Power is generated through planar electromagnetic induction using a magnet on the low frequency actuation plane, and coils on the high frequency resonance plane. The proposed approach has been demonstrated using a macro-scale prototype, which provides 5.1 μW maximum power and 11.1 mV maximum voltage. When scaled to micro-electromechanical (MEMS) dimensions, the expected maximum power and voltage from the 10 × 8.5 × 2.5 mm³ generator is 119 nW and 15.2 mV respectively. This system provides more than three orders of magnitude improvement in energy efficiency for 70-150 Hz ambient vibration range, compared to the first generation MEMS Energy scavenger module.