Electromechanical finite element analysis for designed low-frequency MEMS piezoelectric vibration energy harvester

This work presents an electromechanical finite element analysis for a proposed MEMS piezoelectric vibration energy harvester. The structure of the MEMS energy harvester consists of a basic cantilever beam with a clamped end mass and a spring net which can enhance the reliability of the device. Aluminum nitride thin film is applied as the piezoelectric function material. The proposed MEMS device is also fabricated, packaged and characterized to determine its performance. The spring net structure design is proven to increase the yield of the MEMS energy harvester chips during transportation. Three dimensional electromechanical finite element model coupled the solid mechanics physics and electrostatics physics is built to simulate the piezoelectric effect. The simulated results and the experimental measured data are in close agreement, which verified the prediction of the finite element model. The validation of the model indicate that the finite model can instruct the design of an ideal MEMS piezoelectric device in short period at a low cost.