A new Tapered-L shaped springs based MEMS piezoelectric vibration energy harvester designed for small rolling bearing fault detection

This paper examines the simulation-based performances of piezoelectric MEMS vibration energy harvester made up of two Tapered-L shaped springs and one seismic mass, which is designed for supplying energy to the bearing fault observing device or else identifying the defect in small bearing. The proposed novel structure having PZT-5A piezoelectric material is designed and analyzed in finite element method simulator COMSOL by utilizing vibration data-based comparison results of healthy and defective bearing from an experimental setup. Time domain analysis, fast Fourier transform, and Morlet wavelet transform are done on acquired vibration signatures to investigate the bearing condition. Experimental results demonstrate 0.09 g and 0.25 g peak acceleration for defect free and defective bearing, respectively. And bearing generated frequency when the ball passes the outer race of the ball bearing is obtained to be 76.3 Hz. Maximum observed power outputs from the Tapered-L shaped device are 22.96 nW and 177.49 nW at 0.09 g and 0.25 g accelerations, respectively over 76.3 Hz resonant frequency and 100 kΩ load resistance.