Modeling and analysis of stretching strain in clamped-clamped beams for energy harvesting

In this paper, the utilization of stretching strain that exists in clamped-clamped beam structures is investigated as a main source for energy harvesting from vibrations using a piezoelectric material. This technique eliminates the need for a substrate material, and reduces the electrodes configuration complexity, thus simplifies the fabrication process. This structure exhibits nonlinear dynamics under certain conditions, which is modeled as a single degree of freedom (SDoF) electromechanical system. The proposed model accuracy is then verified using finite element modeling (FEM). The results show a highly nonlinear system with a “Duffing” frequency response that can be used to design an ultra-wide bandwidth energy harvesting system suitable for practical applications. Using this technique a design of 9.9mm 3 energy harvester is proposed using polyvinylidene fluoride (PVDF) that can generate up to 4μW from vibrations of 0.5g at 70Hz.