Mechanism and basic characteristics of a helical inflatable gripper

Weight saving is required at ends of robot arms. This research proposes an extremely lightweight gripper which twines helically. It is composed of an inflatable soft actuator by utilizing plastic films with pleated structures. There are two advantages to the gripper (1) The improvement of the force generated by the increase in the contact area with the target object (2) The ability to twine which is not bound by the object shape. The difference of pneumatic artificial muscles and our researched actuators: (a) Lightweight extremely by using a plastic film, (b) Possible easily to obtain the output by utilizing structural deformation rather than elastic deformation, (c) Difficult to realize the twining movement for elasticity of the rubber. In this paper, we developed a helical inflatable gripper and several characteristics of gripping force are indicated experimentally. From the experimental results, the gripper of the weight of 40[g] achieved the gripping force of 15[N].