Theoretical and experimental studies on bistable vibration energy harvester with levitation magnet couple

To improve the efficiency of vibration energy harvesting, a levitation magnet couple is introduced to the bi-stable energy harvester (BEH) to create a desired potential energy, by which the harvester's response and output can be increased greatly. Compared to the classical BEH, the novel harvester has a lower potential barrier and a flatter bottom of its potential well, which can help increase the response and outputs. The experimental results show that the introduction of levitation magnet couple effectively extends the working frequency bandwidth of the harvester. The inter-well jump can be executed easily under weak stochastic excitations and the amplitude is larger than the classical one, even in the case of executing the same kind of intra-well oscillation. The experiments prove that the output voltage of the novel harvester outperforms the classical BEH over the whole intensity range. This study may provide a good guidance to improving the performance of bistable energy harvester.