Fe-Ga 合金（Galfenol）を用いたマイクロ磁歪振動子

抄録

Micro magnetostrictive vibrator using Iron-Gallium alloy (Galfenol) was investigated. Galfenol is an iron-based magnetostrictive material with the magnetostriction more than 200 ppm, high permeability μr > 100 and Young's modulus of 70 GPa. The material is machinable to free of the shape by conventional cutting process, and sustainable for tensile, bending, and impact. Micro actuator using Galfenol equipped with iron yoke and winding coil, therefore, has advantages over PZT type, in simple, low voltage driving, high robustness and wide temperature operation range. This paper describes the performance of a micro vibrator improved to our previous prototype, in configuration, material, and fabrication process. The vibrator using stress-annealed Galfenol machined to the rod of 1mm diameter was observed the displacement of 1.2μm, high bandwidth of 30 kHz and high tensile robustnesswithstanding suspended weight of 500g. The vibrator was also verified useful as speaker which can generate clearsound from the power of a portable music player.