Analysis of frequency characteristics of MEMS piezoelectric cantilever beam based energy harvester

In this paper, the parameters effect on resonant frequency of MEMS piezoelectric cantilever beam is studied by FEA simulation, which is aimed to provide estimation of the frequency error using simple beam formula for piezoelectric cantilever beam based vibration energy harvester. In the simulation, piezoelectric vibration energy harvester is simplified to a thin silicon cantilever beam with a proof mass attached at the free end; the frequency error (Er) was achieved from the difference of simulation value and the value determined by beam formula, and its three main parameters width to length ratio of cantilever beam, covering area of proof mass, and mass ratio of proof mass to cantilever mass are systematically analyzed with a range of 0.1 to 1, 0.05 to 0.6, 0.5 to 150 respectively; multiple linear regression analysis was used to evaluate these parameters effects. The results show that Er increases with each of these three parameters; the covering area of proof mass has the greatest effect on Er; the range of parameters should be carefully considered to avoid big frequency error using beam equation; the simulation results can be used to guide the design of piezoelectric cantilever beam based vibration energy harvester.