This paper presents a passive joint using shape memory gel. Compliance is effective for the robot arm when it touches the environment. Low stiffness robots are effective for contact tasks and the high stiffness ones are effective for precise positioning tasks. The variable stiffness robots can be used for the both tasks. The shape memory gel has high stiffness at room temperature and low stiffness at high temperature. We have developed a one-degree-of-freedom passive joint using shape memory gel. The passive joint has been designed so that it is attached to the wrist of the robot arm. A basic experiment is performed to show that compliance of the joint can be changed.
