Design，fabrication and performance test of a micromachined permanent magnet vibration-based power generator

Abstract:

This paper presents a permanent magnet vibration-based power generator based on Micro Electro Mechanical Systems(MEMS) technology. It can scavenge vibration energy and convert it into electrical power. It includes a fixed micro coil and a movable permanent magnet attached on a nickel planar spring integrated with silicon frame. The two-layer copper micro coil and nickel planar spring on silicon are fabricated using bulk-silicon micromachining and microelectroplating technique. Two prototypes with different coils and same magnet-spring system are assembled and tested. Prototype A can generate maximal load voltage of 51 mV and load power of 5.89 μW at 222 Hz resonant frequency and 9.8 m/s2 acceleration. At the resonant frequency of 247 Hz，prototype B generates maximum load voltage of 62 mV and load power of 6.4 μW for acceleration of 9.8 m/s2. The coil’s area of 6.25 mm2 in prototype B is only 28? of that of 22.56 mm2 in prototype A，however，the load voltage and load power are increased by 21.6? and 8.6?，respectively. The analysis about the difference of output performance of two prototypes is also given in this paper.