A variable-stiffness actuator includes a shape-memory member that has an end and another end and increases in stiffness on heating, and a heating member that is arranged along a longitudinal axis of the shape-memory member so as to surround an outside of the shape-memory member and receives a current to heat the shape-memory member. The variable-stiffness actuator also includes a conductive member arranged around an outer periphery of the heating member, so as to physically protect the heating member. The conductive member is electrically connected to the heating member.
