Vibration Energy Harvesting Using Bimorph Piezoelectric Cantilever

Vibration energy harvesting with piezoelectric material can currently generate up to 300 microwatts per cubic centimeter, making it a viable method of powering low-power electronics. A problem in piezoelectric unimorph energy harvesting is to generate the most power with limits in system mass. This paper studies the effect of a piezoelectric bimorph cantilever beam harvester shape on its electromechanical performance. A semi-analytical mechanical model was developed using Rayleigh–Ritz approximations for piezoelectric energy harvester with tapered bimorph cantilever beam. A coupled field simulation model for the harvester is constructed using MATLAB and ABAQUS software to study the effect of varying the length and shape of the cantilever beam to the generated voltage and verification study is performed. Design optimization on the shape of the harvester is done to maximize output power. It is shown that tapered beams lead to a more uniform strain distribution across the piezoelectric material and increase the harvesting performance.