A Gripper with Wave Joint Fingers for Precision Grasping

Advances in robotic manipulation are increasingly expected and requested in the scientific field. In fact, robotic manipulators and grippers allow to enhance many industrial, medical, and everyday activities especially if they can mimic the precision and dexterity of the human hand. From this perspective, different kinds of grippers can be developed in terms of number of fingers, actuation, and design characteristics, based on the specific task they have to accomplish and on the kind of grasping they have to perform: power or precision grasping. In this paper, a new three-finger gripper is proposed to perform precision grasping. For this purpose, the gripper is provided with a new version of monolithic wave-joint fingers in which the position of the joints is not aligned, and the last joint and phalanx are not actuated. The gripper is an underactuated, tendon-driven device where a new differential system allows the actuation of all the fingers ensuring the compliance of grasping. The paper describes and discusses the design of the gripper, and a sample experiment is performed to assess the precision grasping abilities of the new robotic device.