Modeling and parametric analysis of a unimorph piezocomposite energy harvester with interdigitated electrodes

This study investigates the derivation of an accurate parameterized analytical model of a vibration-based energy harvester using piezocomposite material and interdigitated electrode. The derived model is used to analyze and optimize the harvested electrical energy under different resistance loads and excitation frequencies. The energy harvester is composed of a unimorph design cantilever beam partially covered by a piezocomposite material with interdigitated electrodes. The model provides an improved approach to optimize the performance of the system by taking into account the nonlinear electrical potential distribution and nonuniform vibration mode shapes over the beam's length due to the presence of the piezocomposite patch. We use a Galerkin procedure along with the Gauss's law to derive the analytical reduced-order model and study the dynamic response of the energy harvesting system. We demonstrate that different parameters are involved into the optimization process of the system such as the number of electrodes, the different layer thicknesses, the piezocomposite patch length, the fiber volume fraction and the substrate material. The proposed analysis shows that significant increase of the harvested energy could be obtained if all design parameters are correctly chosen. A numerical finite element model is also developed to validate the obtained analytical results.