Remember that compliant "jamming" end effector unveiled by Colin Angle (iRobot CEO) at TEDMED 2009? Even then, it was demonstrated picking up medication bottles, keys, and water bottles (a hand-held version was also demonstrated). Well, it just got a whole-lot more official with the publication of "Universal robotic gripper based on the jamming of granular material" in the Proceedings of the National Academy of Sciences (PNAS). The cool thing about this method of grasping is its relative simplicity: a rubber sack (balloon) filled with coffee grounds is pressed onto an object, it conforms to the object's natural contours, and the air is pumped out (a volume change less than 0.5%) to form a stable grasp-- no complex grasp planning required. Be sure to check out the new video and photos!

Update on Oct 28th, 2010: John Amend, co-author of the PNAS article, wrote in to share this updated video with voice-over.

The latest effort is a joint effort between U. Chicago, Cornell, and iRobot. Here is a video of the robot grasping all sorts of objects (eggs, LEDs, tubing, light bulbs, pens, etc.), pouring water, and writing with a pen.

Here is a brief diagram explaining how this method works, directly from the PNAS article.

ScienceMag discusses some of the limitations:

The hand works best on hard, dry, geometrically complex objects like screwdrivers and toy jacks. It has more trouble with flat objects like plastic discs and porous objects like cotton balls, because the air holes weaken the suction. It also can't grip anything bigger than half its size—the biggest items the team picked up were two one-gallon jugs of water. But the hand's true strength, according to engineering student and co-author John Amend of Cornell University, is its versatility. Aside from the limitations noted above, he says, as long as the gripper can fold about one-fourth of the object's surface, it can pick up just about any shape thrown in its path.

You'll notice that this latest version is very similar to the version Hizook covered previously (from Colin Angle's TEDMED 2009 talk):