Design and performance of a microelectromagnetic vibration powered generator

In this paper we, report on the design, simulation and initial results of a microgenerator, which converts external vibrations into electrical energy. Power is generated by means of electromagnetic transduction with static magnets positioned either side of a moving coil located on a silicon structure designed to resonate laterally in the plane of the chip. The development and fabrication of a micromachined microgenerator that uses standard silicon based fabrication techniques and a low cost, batch process is presented. Finite element simulations have been carried out using ANSYS to determine an optimum geometry for the microgenerator. Electromagnetic FEA simulations using Ansoft´s Maxwell 2D software have shown voltage levels of 4 to 9 V can be generated from the single beam generator designs. Initial results at atmospheric pressure yield 0.5 μW at 9.81 ms^-2 and 9.5 kHz and emphasise the importance of reducing unwanted loss mechanisms such as air damping.