Design and Experiment of Vibration-Based Miniature Generator

Abstract

To transform endless energy from ambient vibration into useful power. We scavenge mechanical energy and transfer into electrical energy by utilizing piezoelectric materials. We compare generators performance at different situations and then let electric energy be charged to a Ni-MH battery or a capacitor through a full wave rectifier. We also obtain resonance of piezoelectric benders by system identification which can be an important reference when designing the generator. This study proposes a novel mechanism comprising a mass-spring system and magnet repulsive force. According to finite element software and experimental result, below 5 Hz the generator absorbs vibration energy more easily. We have investigated the influence of the mass magnitude and obtained the optimum result of 2.7V and 0.379 mu w when the swinging amplitude of the motor is +/- 1.8 deg at swinging frequency of 3.96 Hz.