The robot gripper wields a brush. But can it paint

If you've got ground coffee and a few party balloons lying around, you have the ingredients for a universal robot gripper, according to researchers at Cornell University, the University of Chicago, and iRobot.

In a report in the Proceedings of the National Academy of Sciences, researchers including Hod Lipson, associate professor of mechanical engineering and computer science at Cornell, describe how they used granular material instead of multijointed fingers to create a robot gripper.

The researchers put ground coffee into a latex balloon and attached it to a robot arm. When the coffee balloon is pressed around an object like a brush, above, it deforms and envelops the target.

When the air is removed from the balloon, the ground coffee solidifies around the brush, forming a firm grip. Apparently, the gripper can also pick up eggs and coins, which are challenging for robot manipulators with fingers.

The gripper makes use of "jamming transition," in which a fluidlike material becomes virtually solid when its particles cannot move past each other in a vacuum. The researchers also tried using materials like couscous, rice, sand, and ground-up tires. Coffee's lightness proved to be a winning quality.

Funded by DARPA, the research could lead to applications such as robot arms that could be used to dismantle explosives or robot feet that could walk up walls, Lipson speculated in a Cornell release.

Spider robots that run on coffee. Sounds like one of those great ideas that can go horribly awry.