Robots Fashion Hands Out of Coffee Grounds, Party Balloons

The robotic gripper developed by researchers from iRobot Corp., Cornell, and the University of Chicago isn’t exactly the human hand-like contraption you might expect from something that can delicately pick up a water-filled glass. Instead, the so-called “universal gripper” looks more a boxing glove or a beanbag.

The gripper, which is actually just a party balloon filled with ground coffee, conforms around an object to pick it up. A vacuum sucks the air out of the balloon, tightening the gripper’s hold. Releasing the vacuum, in turn, triggers the gripper to loosen its hold on the object. The mechanism is so versatile that it can pick up items as tiny as M&M’s.

Hod Lipson, Cornell associate professor of mechanical engineering and computer science, explained in a statement, “The ground coffee grains are like lots of small gears. When they are not pressed together they can roll over each other and
flow. When they are pressed together just a little bit, the teeth
interlock, and they become solid.” Any particulate matter that jams well can be used in theory; the researchers chose coffee after experimenting with ground-up tires, rice, and couscous.  

Unlike complicated hand-like grippers, the balloon and coffee gripper is simple enough that it can quickly go into manufacturing. And once that happens, it could be used in prosthetic limbs, bomb-dismantling devices, on robotic arms in factories–even on robots that walk on walls. A bonus for people using the gripper as a prosthetic hand: they can probably throw a mean punch.

Ariel Schwartz can be reached on Twitter or by email.AS