Improvement of Response Time of Thin Film Unimorpli Structure using Hydrogen Storage Alloy by Platinum Surface Treatment

Abstract

In this study, the effect of the platinum surface treatment on mechanical response of LaNi5 thin film actuator deposited on polyimide substrates was investigated. Since this actuator could be reversibly driven by hydrogen pressure control, this actuator is expected as a sensor and/or controller of hydrogen gas flux in various hydrogen related devices.In the experiments, initiating time of the actuation after hydrogen gas exposure is reduced from 100 to 10 s by platinum surface treatment. This significantly modified mechanical response is attributed to switching of the reaction rate determining steps. Dissociation of hydrogen gas molecules on the sample surface is considered to be changed to permeation/diffusion of hydrogen atoms in the film by the platinum treatment.