Design and Fabrication of a High-Efficiency Magnetostrictive Energy Harvester for High-Impact Vibration Systems

This paper presents the design and fabrication of a vibration energy harvester based on giant magnetostrictive material, which consists of one coil-wound Terfenol-D rod with a permanent magnet (PM) and air gap in each magnetic circuit, and the PM array on the part of a cap amplifier. In this design, cap amplifiers and variable air gap are used to increase the harvesting effect of systems under environmental impact. Modeling and simulation are developed and performed to validate the concept. The relation of magnetic field in Terfenol-D rod is derived, and its uniformity and intensity are analyzed. Then, principal design parameters of the harvester, air gap, and cap amplifiers are determined, and its static analysis of the harvesting effect is performed. In addition, a prototype is fabricated and tested. The magnetostrictive-based vibration energy harvester can generate larger voltage and power than conventional smart harvesters and they can be safely used under the impact up to 20-30 MPa.