Macro fiber composite-based low frequency vibration energy harvester

Abstract

In this paper, we present a vibration energy harvester using a spherical permanent magnet as springless proof mass and a magnetoelectric laminate structure composed of MSMA (magnetic shape memory alloy) and MFC (macro fiber composite) in d(31) or d(33) operational modes. Combination of transduction mechanisms, including magnetoelectric effect and impact-induced vibration of the magnetoelectric laminate composite, generates power from low frequency excitation such as human-body-induced motion. Two different types of magnetoelectric laminate composite based power generators have been fabricated, tested and compared. Moreover, the contributions of individual transduction mechanisms have been analyzed experimentally. Maximum peak-to-peak open circuit voltage of 16.4 V has been obtained in response to a 3 g vibration at 15 Hz for device with d(33) mode MFC. Device with d(31) mode MFC generated maximum output power of 11.2 mu W in vibration exciter test and 82.5 mu W in manual vibration test across an 800 Omega load. Based on the experimental observations, an impact-based harvester with d(31) mode MFC has been proposed, which generated improved output power of 245.6 mu W. (C) 2015 Elsevier B.V. All rights reserved.