Soft Jamming Gripper with the External Prominence of Membrane for Human-Robot Cooperation

Designing grippers as robotic hands is one of the largest challenges in robotics. The process of gripping and moving is achieved in different ways through various models of robotic grippers. Dexterous, careful and useful robotic gripper not necessarily need to be a claw or an artificial hand with several fingers. A promising technical alternative is the so-called jamming gripper, which is made of a flexible membrane filled with appropriate powder, e.g. ground coffee, as an assistive device to join in robots. The purpose of the work described in this paper is to develop a robotic gripper with an advanced surface structure with external prominence to enhance the smooth exterior of the membrane. Tests are performed to determine the influence of the different objects and friction force of the membrane on the gripping performance and holding force of the gripper system. The results show that by improving the outer surface geometry of the membrane, friction is increased under the same condition, e.g. vacuum and pressure, so that heavier objects can be lifted. In particular, the holding force of the uneven surface membrane (USM) is much higher than the smooth surface membrane (SSM) to grip the various objects.