Characteristics of small-scale piezoelectric vibration energy harvesting device for rotating structures

Abstract

The utilization of Karman vortex shedding forces as the primary excitation source is proposed in this study for a piezoelectric energy harvesting device aimed at meeting the long-term self-sufficiency and power generation requirements of small rotary mechanisms. The piezoelectric layer material employed is zinc oxide (ZnO), and the device is affixed to a biased cantilever beam. Simulation analysis of the Karman vortex shedding phenomenon was executed using COMSOL Multiphysics software to derive force variation curves acting on the piezoelectric energy harvesting device at different rotational speeds. The optimal rotational speed was determined, and the force at this speed was applied to the piezoelectric energy harvesting device. Through adjustment of the geometric parameters of the device, the objective was to maximize the voltage output.The results indicate that an increase in the length of the film, a reduction in width, and an augmentation of the thickness of the piezoelectric layer can, to some extent, enhance the output voltage at both ends of the film. When the film length is set at 30 mm, the width at 3 mm, and the thickness at 0.002 mm, the maximum open-circuit voltage at both ends of the film can be achieved at 42.2 V.