Bending behavior of Cu-plated Pd-Ni alloys ribbon driven by hydrogenation

In recent years, human-type robots attract much attention in the field of medical welfare and industrial applications under severe environmental conditions, such as in space. For the realization of such robots, the development of an actuator having superior functions as human fingers is required. It is known that hydrogen storage alloys exhibit a significant volume change of 10-30% on hydrogenation, which is several tens times greater than that caused by thermal expansion. Since the driving force of an actuator driven by hydrogenation is based on phase transformation, the actuator can be expected to show high power. In the present work, a bending module having a sheet form of palladium-base hydrogen storage alloy foils bond with a copper foil was prepared and its bending behaviors were investigated.