As posted previously...In this project, Make Magazine's Jason Poel Smith shows you how to make a universal robot gripper using an ordinary balloon and coffee grounds. Coffee grounds are placed in the balloon. When the balloon is inflated, the coffee grounds are loose and will easily move around an object. But when the air is sucked out of the balloon, the grounds are pulled together and grip the object from all sides. This works because of a process called "jamming": When a granular material such as coffee grounds is compressed, the friction between the grains locks them in place. I may have to make one of these!