Development of an innovative energy harvesting device using MFC bimorphs

Abstract

Recently, widespread attention has been directed towards scavenging energy from renewable sources such as wind. Piezoelectric materials are particularly suitable for capturing energy from motion since mechanical deflection of a piezoelectric specimen results in an electric displacement. This electricity can be stored in batteries or used to power portable devices. The present work is on the development of a device that can generate electricity from an oscillating motion using a piezoelectric Macro Fiber Composite (MFC) bimorph. Previously, bimorph vibration was created by a rotating or reciprocating part hitting the bimorph tip; whereas in the current work, base reciprocation excites the piezoelectric bimorph. The device includes a fan blade, which aligns with the direction of the wind and moves a rod in vertical direction. The microfiber composite beams (MFC) are attached to the upper end of the rod. Reciprocation of the rod acts as a harmonic excitation for the MFC bimorphs. Vibration of the MFCs produces electricity which is stored in a capacitor to be used to power electronic systems such as different types of remote sensors. Simulation and experimental results have been compared. In vibration and wind tunnel experiments, comparable amounts of energy were collected and accumulated in a capacitor.