Mover Device Driven by Hydrogen Storage Alloy Thin Film Operated by Electric Current

摘要

Hydrogen storage alloy, such as LaNi_5 indicates as much as 25% of volume change in the course of H_2 absorption and desorption. We examined to apply this phenomenon to a mechanical mover device as a driving force controlled by the amount of hydrogen in the alloy. In this study a unimorph structural mover device was tested using HSA thin film deposited on an inert substrate. We confirmed displacements generating drastically large stresses by applying H_2 gas. While the amount of hydrogen in the alloy is a function of H_2 pressure and temperature, we also tried to control the hydrogen amount in the HSA by electric current directly applied through the film in a closed system. We report discussions on results with precise relationship between current and displacement under different temperatures. Displacement can be achieved by the temperature change caused by the electric current placed under ambient H_2 pressure, therefore, the results indicate the possibility of mover devices with simple structure similar to an artificial muscle controlled by electric current. From the results obtained, the test device was expected as an artificial muscle driven by hydrogen sorption reactions, which could be also controlled by electric current.