Development and fatigue testing of a PZT assembly with PE housing for harvesting mechanical energy

Abstract

This paper presents the results of simulation of design and a real fatigue test of a protected PZT assembly for energy harvesting application. The protection was from a new encapsulation design. Based on a previous unpublished research, simulation runs with ANSYS program to simulate the effect of stress on Polyethylene (PE) protective layers of various shapes were performed and the results demonstrated that PE layers of rectangular shape were able to distribute an external pressure at a suitable amount to the PZT sheet and withstand repeated pressings from an external pressure in the range of 5-20 MPa. These results enabled us to choose the best shape of PZT sheet and PE housing assembly. The fatigue parameter of the assembly was determined by subjecting the assembly to a repeated external force. And the voltage cycle of the encapsulated PZT assembly was measured with an oscilloscope. The voltage cycle test results show similarly-shaped cycles with a mean voltage of 3.76 V both before and after the assembly was subjected repeatedly to an external force. The fatigue parameter was defined as a minimum voltage that the assembly could deliver after a large number of repeated pressings by an external pressure in the range of 5-20 MPa. Our criterion of successful protection was a minimum of 3.5 V after 4,500 pressings. Therefore, we concluded that the constructed assembly was able to withstand an external operating pressure satisfactorily.