Modeling and simulation of piezoelectric MEMS energy harvesting device

Piezoelectric MEMS power generator is used to harvest energy from the ambient vibrations in the environment. This paper proposes a structure design of MEMS power generator for low-frequency applications, which is based on bulk MEMS technology and (110) Si wafer. The structure consists of a silicon cantilever with a piezoelectric layer attached. The cantilever is modeled as an Euler-Bernoulli beam with a lumped mass beneath the tip of the cantilever, and then analytical modeling and simulations are carried out using MATLAB. Simulation results show that a tradeoff between the geometric parameters and the proof mass should be made for a high output power of the device. To increase the output power, the length of piezoelectric layer can be optimized, which is not necessarily equal to that of cantilever. Simulation results point out ways to perform the optimization of MEMS power generator. The analytical modeling and simulations are also helpful for the design of macro-scale power generator.