RoboticsRobotic attachment uses balloon, coffee to grasp objects

Published 27 October 2010

DARPA-funded research yields a new robotic gripping attachment which relies on ground coffee and a party balloon; The manipulator presses a soft balloon full of loose coffee grounds down on the object to be gripped; the air is sucked out of the balloon, causing the coffee granules to press together and lock into a rigid shape — causing the object to be securely grasped by the manipulator; the object can be released as desired by ending the suction on the granule-filled bulb

Robotics researchers have developed an intriguing new accessory — a squashy “gripper” manipulator which can be fashioned out of ground coffee and a party balloon.

The manipulator works by pressing the soft balloon full of loose coffee grounds down on the object to be gripped. Then the air is sucked out of the balloon, causing the coffee granules to press together and lock into a rigid shape — just as they do when vacuum-packed. The object is now securely grasped by the manipulator, and can be released as desired by ending the suction on the granule-filled bulb.

According to professor Hod Lipson, one of the researchers working on the device, it “could be on the market tomorrow.”

The ground coffee grains are like lots of small gears,” adds Lipson. “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.”

Lewis Page writes that the coffee-balloon gripper research was carried out at academic labs in Chicago and New York state, and private ones belonging to automation firm iRobot, well known as the manufacturer of the Roomba prowler-cleaning machines and as a supplier of battle robots to the U.S. military.

Apparently various types of granular material were tried out for the gripper, including rice, couscous, and ground-up car tires. Page writes that sand was apparently even grippier than coffee, but “prohibitively heavy.”

The research was for DARPA, the Defense Advanced Research Projects Agency.

—Read more in Eric Brown et al., “Universal robotic gripper based on the jamming of granular material,” Proceedings of the National Academy of Sciences (25 October 2010) (doi: 10.1073/pnas.1003250107)