MEMS Energy Harvester Utilizing a Multi-pole Magnet and a High-aspect-ratio Array Coil for Low Frequency Vibrations

This paper presents a new micro-electromagnetic power generator with a large output power density for the application of low frequency vibrations (≤10 Hz). The 16-poles thin magnet plate (8.9×8.9×t0.5 mm) alternately magnetized with a chessboard pattern by laser assisted heating helps enhance the magnetic field to coils. The high-aspect-ratio microarray coil (4 x 6 matrix, coil width: 80 μm, coil thickness: 160 μm, total turns: 144/coil unit) fabricated by thick micromolding is beneficial for increasing coil winding density and reducing its resistance. The fabricated prototype is proved to generate 1.63 mV at 10 Hz and 2 mm excitation. This corresponds to a maximum output power of 0.12 μW and a maximum power density of 1.03 μW/cm
³
.