Modeling and Analysis of Micro-cantilever Plate Piezoelectric Energy Harvester with a Tip Mass

With the development of MEMS (Micro-electro-mechanical Systems) techniques, research interest has deepened in micro piezoelectric harvesting device, which can supply electrical power for wireless sensors from ambient vibration. This paper proposes a nonlinear analysis of a micro-scale PEH (piezoelectric energy harvester), which is modeled by a micro-cantilever plate with two layers and a tip mass attached to the free end. Considering size effect and nonlinear curvature, based on strain gradient and inextensible plate theory, nonlinear dynamic equations of the micro cantilever piezoelectric energy harvester with tip mass are established by virtue of the Hamilton’s principle. The maximum output voltage of piezoelectric energy harvester with different tip mass is calculated respectively using MATLAB software. Comparative analysis confirms that an increase of K (the mass ratio of the tip mass to piezoelectric plate) reduces the natural frequency of energy harvester and significantly enhances the nonlinear phenomenon. In addition, when the mass ratio K exceeds 1, obvious superharmonic resonance phenomena generates, which considerably improves the output voltage of the proposed PEH in a lower frequency band. This study proposes an approach to enhance the output performance of micro-cantilever plate energy harvesters and broaden the bandwidth of PEH to adapt low-frequency ambient vibration.