Chemical Composition Dependence of the Properties of a LaNi_x (x=3.8 to 6.5) Hydrogen Storage Alloy Film Actuator

Abstract

Hydrogen storage alloy, accompanied by a volume expansion of more than 24% by hydrogenation, exhibits enormous high levels of expanding force. An actuator using this phenomena functioning by hydrogen pressure change may exhibit both drastically large fore and shape changes. Hydrogen storage alloy is, however, pulverized by the hydrogenation, therefore, thin film in about 1 μm thick of a hydrogen alloy was used as actuator material, which was not pulverized by the hydrogenation. Compositional dependence of LaNi_x (x=3.8 to 6.5) on the actuation behavior was investigated in this study. The largest displacement was observed for the test device with the composition of LaNi₅, which indicated the largest storage capacity for the hydrogen.