Influence of Booster’s Geometry and Circuit’s Resistor on Performance of the Auxetic Energy Harvester - Experimentally Validated Analysis

Modal and frequency response analysis of the piezoelectric energy harvester utilizing the auxetic booster has been performed in this paper. This harvester has composed of a cantilever, auxetic substrate, and piezoelectric layer. The influence of the piezoelectric’s electrical circuit and the harvester’s geometrical properties on the fundamental natural frequency, output voltage, and harvested power of the energy harvester have been investigated. The electrical circuit of this electromechanical system consists of a resistor that influences the energy harvester's output voltage and harvested power. A comprehensive parametric study has been performed to find the optimum resistor of the energy harvester. All the analysis has been performed using the finite element method. Mesh size sensitivity analysis of the models is presented, and the finite element model is verified by previous experimental studies. Furthermore, the effect of this energy harvester's damping ratio on the system's outputs has been investigated. The results show that the system's output alters considerably in different damping ratios, and it is necessary to determine the system's damping ratio of the system. The damping ratio of the auxetic energy harvester has been measured through the experimental investigation. The present study illustrates that harvested power of a trapezoidal auxetic energy harvester in resonant frequency could improve by 260 percent by utilizing the optimum resistor. Also, increasing the auxetic booster's thickness could improve the output voltage and harvested power by 48 percent and 22 percent.