Modeling and performance analysis of a novel M-shaped piezoelectric energy harvester employing magnets

Piezoelectric energy harvesters convert the vibration energy of a mechanical system into the electrical energy. Among them, cantilever type is the most popular one. With the cantilever type harvester, however, generated voltage decreases rapidly when excitation frequency deviates from the natural frequency of the harvester. To overcome the weakness and achieve good voltage generation performance, we proposed a new M-shaped energy harvester using two sets of magnets. We derived the coupled electromechanical equations and investigated the performance of generated voltage and power using the equation model. By controlling the distance between two magnets in a set, we could design an energy harvester having either a large single peak or broadband voltage frequency response characteristic. We could also achieve a better power generation performance with the novel M-shaped piezoelectric harvester.