Study on sponging rubber actuator covered with silicon

When a care taker have to assist many handicapped people, the person sometimes feels backache because of the holding up motion involved. Therefore, in order to relief the pain, some care takers attach a protection belt to the lumbar part. However, since the compliance of the belt is constant, it is difficult to bend the waist to assist elderly people. In this paper, we propose a new type of actuator to apply to the protection belt. The actuator has a structure that a sponge is covered with silicon rubber. Thus, it is possible to control the stiffness of the actuator according to the user´s posture. From experimental results, the effectiveness of the actuator is confirmed.