Abstract
We are developing vibrational energy harvesting system using iron-based magnetostrictive material (Galfenol) utilized as power supply for wireless sensor module of automobile and industrial machinery. The harvester consisting of Galfenol plate wound with coil, yoke and magnet features simple, small, highly robust and high power output. Our conventional harvester based on cantilever can generate high power output at high frequency resonance, however, does not match the use in automobile and industrial machinery with 10w frequency vibration. In this paper, we propose harvester equipped with adjusting tip mass mechanism and resonator for the operation in low frequency vibration. The harvester with the mechanism has three low frequency resonances determined by tip mass, mass and spring of the resonator. We verified the prototype using Galfenol plate of 2 by 0.5 by 22 mm with the mechanism (tip mass of 7.4g) has resonant frequency around 63 Hz and can generate high power output at low frequency and wide bandwidth.