Dynamical Modeling and Simulation of a Laser-micromachined Vibration-based Micro Power Generator

The dynamical motion of laser-micromachined copper springs used for a meso-scale vibration-based power generator was successfully modeled using ANSYS to reveal 3 modes of multi-directional vibratory motion due to a pure vertical input vibration. A MATLAB simulation was also used to predict the voltage output of the micro power generator system with coupled electrical and mechanical damping effects. The simulated output matched experimental results closely. These capabilities are essential for the successful design and development of a miniature, low-frequency, and robust micro energy generator that could be potentially used to convert human mechanical energy into usefully electrical power to operate devices such as mobile phones and heart-pacers. Thus far, 1cm³ meso-scale generators are demonstrated capable of producing up to 4V AC with instantaneous peak power of 80mW, at input frequencies ranging from 60 to 120Hz with ∼200μm input vibration amplitude. A generator capable of producing 2V DC output with 40μW power after voltage rectification, and able to drive a commercial infrared wireless signal transmitter to send 140ms pulse trains with ∼60sec power generation time was also demonstrated. The ANSYS model and MATLAB simulation results are presented and compared with the experimental results in this paper.