Magnetoelectric Energy Harvesting from Vibrations of Multiple Frequencies

A novel multi-frequency vibration energy harvester has been designed and fabricated, which consists of two cantilever beams, two magnetoelectric (ME) transducers and a magnetic circuit. In the harvester, the magnetic forces between the ME transducers and the magnetic circuit will result in additional magnetic stiffness on the two cantilever beams, on which the frequency response of the harvester is highly dependent. In addition, the magnet circuit should provide the best magnetic field conditions for the ME transducers to obtain large ME conversion outputs. Therefore, in this article, a theoretical model is developed to analyze the effects of the structure parameters on the frequency response and the electrical-output for achieving the optimal vibration energy-harvesting performances. A prototype was fabricated and tested. The experimental results showed that, the harvester had a bandwidth of 5.6 Hz and a maximum average power value of 0.25 mW at an acceleration of 0.2 g (with g = 9.8 m/s(2)).