Design and construction of magnetostrictive energy harvester for power generating floor systems

In this paper, a new prototype of magnetostrictive-based vibration energy harvester for power generating floor systems is presented, and its structure is constructed. The harvester utilizing the Villari effect (inverse-magnetostrictive effect) consists of a coil-wound Terfenol-D rod. To generate more electrical power, a PM (fixed on the part of cap amplifier) and variable-length air-gap are designed in each magnetic circuit, which helps to enlarge Villari effect in Terfenol-D rod in the action of environmental vibration. The magnetic field and its leakage in harvester are analyzed, and principal design parameters of harvester are optimally determined. Then, a prototype is fabricated and tested, and its harvesting effect is calculated. The harvester exhibits high power density, can generate up to 0.022 T/MPa piezomagnetic effect and safely used in up to 20MPa transient impact.