Granular Jamming Gripper (Universal Gripper)

颗粒阻塞夹爪Advanced

A soft bag of granules that molds around an object, then hardens under vacuum to lock it in place.

A granular jamming gripper consists of a soft balloon-like bag filled with granular material, such as coffee grounds or sand. To grasp, the soft, loose bag is first pressed onto the object, molding itself around the object's shape; then air is drawn out of the bag, the grains pack tightly together and stop flowing past each other (a physical transition called jamming), and the bag instantly stiffens, gripping the object through a combination of friction, suction, and geometric interlocking; releasing it is as simple as letting air back in. It was proposed by researchers at the University of Chicago, Cornell University, and iRobot in a 2010 PNAS paper, and earned the name “universal gripper” because it needs no prior knowledge of an object's shape and can grasp small objects of almost any shape. Its weakness is that it performs poorly on large, flat objects.

ExampleThe same coffee-grounds balloon gripper can pick up a coin, an egg, and a screwdriver without ever changing fingers.

Also called: Universal Gripper, Jamming Gripper, Coffee-Balloon Gripper
Related: Soft Gripper · Gripper · Vacuum Suction Cup · Soft Robot · Compliance
Sources: Jamming (physics) - Wikipedia