Vibration based electromagnetic micropower generator on silicon

This paper discusses the theory, design and simulation of electromagnetic micropower generators with electroplated micromagnets. The power generators are fabricated using standard microelectromechanical system processing techniques. Electromagnetic two-dimensional finite element anlysis simulations are used to determine voltage and power that can be generated from different designs. This paper reports a maximum voltage and power of 55 mV and 70 μW for the first design, incorporating microfabricated two-layer Cu coils on a Si paddle vibrating between two sets of oppositely polarized electroplated Co50 Pt50 face centered tetragonal phase hard magnets. A peak voltage and power of 950 mV and 85 μW are obtained for the second design, which includes electroplated Ni45 Fe55 as a soft magnetic layer underneath the hard magnets. The volume of the device is about 30 mm3.