Investigation of Design Parameters in MEMS Based Piezoelectric Vibration Energy Harvester

This paper presents a Micro Electro Mechanical system (MEMS) based Vibration Energy Harvester (VEH) to harvest energy from external vibration sources and convert it to usable electrical output. Detailed simulation and analysis of Vibration Energy Harvester (VEH) is done to achieve better performance. Finite element analysis software ANSYS has been used for parametric analysis and measure beam displacement, resonant frequency, and output power of the VEH. Different important parameters like beam length, thickness, width, position of mass placement, different piezoelectric material etc. were varied to improve the performance of the device. The 33 mode of operation is used to get the output from the vibration energy harvester. Simulation result shown that to obtain better output from VEH (a) the beam length should be large, (b) beam thickness and width should be small, (iii) mass length, thickness and width should be large. For a Unimorph device of total size of 1500x900x500 mu m(3), an output voltage of 200 mV is obtained when 1N force is applied on the structure.