The benefits of a magnetically coupled asymmetric monostable dual-cantilever energy harvester under random excitation

Piezoelectric vibration energy harvesting is a promising technique to power wireless sensor networks. This article originally presents a magnetically coupled asymmetric monostable dual-cantilever piezoelectric energy harvester consisting of a generating piezoelectric cantilever beam and an auxiliary cantilever beam. Theoretical and experimental results both verify that the asymmetric harvester has the superior performance compared with the conventional magnetically coupled symmetric bistable dual-cantilever piezoelectric energy harvester, yielding higher voltage output under different magnetic coupling intensities and different power densities of the band-limited Gaussian white noise random excitation. More importantly, the mechanical strain of the asymmetric harvester is much smaller than that of the symmetric harvester, being lower than half of the latter one under strong magnetic coupling. Therefore, due to its higher energy conversion efficiency and better durability, the proposed asymmetric harvester is beneficial for practical environment vibration energy harvesting.