Magnetostrictive Vibrational Power Generator toward Practical Application

Abstract

Vibration based power generation technology is utilized effectively in various field. Author invents novel vibrational power generator using Fe-Ga alloy, iron-based magnetostrictive material, with large inverse magnetostrictive effect, good machinability and high ductility. The generator is based on parallel beam structure consisting of Fe-Ga plate wound with coil and yoke accompanied with bias magnet. When bending force is applied on the tip of the generator, the magnetization inside the plate varies with induced stress due to the inverse magnetostrictive effect. In vibration, the time variation of the magnetization generates voltage on the wound coil. The magnetostrictive type is advantageous over conventional such using piezoelectric or moving magnet types in high efficiency and high robustness, and low electrical impedance. Author has established device configuration endurable for practical applications. This paper describes the principle and merit of magnetostrictive type, the evaluation results of miniature prototype, its problem and future potential.