Effect of PZT patch length on Piezo electric Energy Harvester

All structures in nature have vibration energy which can be converted into Electrical energy. This electrical energy can be used as a source of energy to operate sensors thereby replacing limited storage capacity equipment's such as battery. Piezoelectric vibration energy harvesting scheme utilizes direct piezoelectric effect to convert mechanical energy into electrical energy. The output voltage from the piezoelectric vibration energy harvester depends on the relative motion between the base and proof mass. The resulted mechanical strain developed on the PZT patches is converted into electrical power because of direct coupling piezo electric effect. This article present a study of the effect of length of PZT patch on single modal linear vibration based piezo electric energy harvester (PEH). A coupled series piezo patch-electrical circuit finite element model is used to analyze the power output of a vibration based piezoelectric energy-harvesting device (EHD) when it is connected to a load resistor. Mathematical model of linear single modal Vibration -based Energy harvester is developed using Ansys APDL (Ansys parametric design Language). The modeling configuration is done with a series configuration of piezo electric layers. Accuracy of the developed FEM model is validated against the existing coupled FEM model. First modal analysis is performed to find the natural frequency of the piezoelectric energy harvester. Then harmonic analysis is carried out to estimate the voltage responses and power output which are measured through the PZT patches.