Improvement of Bending Motion by Catalyst Addition of Pd-Al₂O₃ Powder for an Uni-Morph Soft Device Constructed of Polymer Sheets with and without Powder Dispersion of Hydrogen Storage Alloy

Abstract

In order to generate the soft bending motion driven by pressure change in hydrogen gas, a soft device was made up and tested. In former research, a unimorph structure was proposed, in which a silicone rubber with LaNi₅ alloy powder distributed was piled up on a pure silicone rubber sheet. Using this structure we succeeded a bending motion of the soft device by applying hydrogen gas pressure. However the mechanical response was slow. To improve the active motion, a catalyst of Pd-Al₂O₃ powder was mixed into the hydrogen storage alloy powder in the rubber. By simple addition of catalyst powder before dispersion into the rubber, we obtained drastically modified responses and displacement in the movement of the device. The catalyst probably accelerated dissociation of hydrogen molecule on the surface of hydrogen storage material particle.