Piezoelectric cantilever-pendulum for multi-directional energy harvesting with internal resonance

Abstract

Piezoelectric transducers are widely employed in vibration-based energy harvesting schemes. Simple piezoelectric cantilever for energy harvesting is uni-directional and has bandwidth limitation. In this research we explore utilizing internal resonances to harvest vibratory energy due to excitations from an arbitrary direction with the usage of a single piezoelectric cantilever. Specifically, it is identified that by attaching a pendulum to the piezoelectric cantilever, 1:2 internal resonances can be induced based on the nonlinear coupling. The nonlinear effect induces modal energy exchange between beam bending motion and pendulum motions in 3-dimensional space, which ultimately yield multidirectional energy harvesting by a single cantilever. Systematic analysis and experimental investigation are carried out to demonstrate this new concept.