Piezoelectric stack energy harvesting with a force amplification frame: Modeling and experiment

This article presents the modeling and experimental validation of a piezoelectric stack energy harvester with a flexure-free convex force amplification frame to convert walking force into electricity. Compared to a stand-alone piezoelectric stack, experiments show an 8 times greater voltage output and a 112 times greater power output of such an energy harvester. A finite element method is used to provide a more accurate electromechanical model using Hamilton's principle and the piezoelectric constitutive equations. Simulation results from such a finite element method agree with the single-degree-of-freedom model. Experimental measurement shows the percentage errors of the output power are of 3.53% for the finite element method and 8.04% for the single-degree-of-freedom model of the piezoelectric stack energy harvester.