Non-Prismatic Energy Harvester for Rotating System

Abstract

The present study investigates the analysis and design of a vibration-based energy harvester, which can be used for rotary motion applications. The energy harvester system consists of a piezo-laminated tapered cantilever beam with a tip mass which is mounted on the hub of a rotating shaft. The tapered beam (both in width and height directions) has a piezoelectric patch at its root. When the shaft is rotated, the beam vibrates which induces mechanical vibration energy in the beam due to the gravitational force applied to the tip mass. The Euler-Bernoulli beam theory is considered for the modelling of the beam. The electrical model is based on a purely resistive circuit. Two piezoelectric patches are considered which are connected in parallel with each other. The electrical circuit equation is formulated using the Kirchhoff’s law. This model is assumed to be coupled with the mechanical system, which converts the vibration energy into electrical energy. The effects of the tapers on the output power are also analyzed. Various geometric profiles such as linear, parabolic and cubic profiles are also considered and analyzed.