A MEMS-based Bi-Stable Electromagnetic Energy Harvester with an Integrated Magnetization-Reversible Circuit

This paper presents the first MEMS-based bi-stable electromagnetic energy harvester with polarity-reversible integrated closed magnetic circuit. The mechanism of polarity reversal in micro-scale closed magnetic circuit is utilized to maximize the flux variation rate, and the overall size and fabrication tolerance of the proposed device are effectively reduced with integrating closed magnetic circuit and resonant structure. Bi-stable configuration with shallow potential barrier less than 3.6μJ is achieved to trigger and sustain inter-well oscillation in micro-scale. It’s experimentally and numerically shown that at the acceleration of 1g, a large bandwidth of 75.2Hz with power output of 146.3μW is obtained, and significant normalized power density (NPD) of 203.2μWcm-3g-2 is simultaneously achieved.