Piezoelectric energy harvesting from highly flexible cantilever beam

Abstract

In many studies, linear or small deflections according to Von Karman strain model are used for energy harvesting of beam’s structures. Analyses of these types are not reliable when deformations become large. In this work, an integro-differential equation of highly flexible cantilever beam with a piezoelectric layer is presented. The harvester is composed of a thin flexible beam with attached piezoceramic which undergoes large deformations. Periodic and chaotic oscillations and their effects on the quality of harvesting energy procedure are investigated. The obtained results showed that chaotic oscillations improve energy harvesting. This means that large deflections in high-flexible electromechanical systems let harvester to gather more energy from the external source in a much wider frequency domain. Fast Fourier transform shows the emerging lots of resonance peaks in the chaotic region, which give cascade of resonances for this highly nonlinear beam. Moreover, it is discussed how this mechanism and its frequency characteristics enhances the quality and quantity of energy harvesting. The present study show how increasing the flexibility of structure can lead to high deflection and obtaining broadband energy harvesting with better energy harvesting characteristics.