The art of lifting an egg

19 February 2011 - Soft robotics

soft robots Ilievski 2011.gifGeorge Whitesides and DARPA have joined forces to bring you another innovation in robotics. Problem: regular robots are clumsy when it comes to handling soft materials when the robot shell is a hard material. A robot picking up a raw egg must have a good sense of the amount of force it can apply if it want to avoid disaster. Solution: fit the robot with a soft shell as well. In the accompanying pic a plastic gripper is lowered, an egg is grabbed and then successfully lifted (Ilievski et al. DOI). This gripper is made up of a core of starfish-shaped polydimethylsiloxane. This section has channels in it that allows pressurized air to enter and exit the arms. It is cast from a mold based on ABS produced in a 3D printer. The core is flanked by two layers of another silicone elastomer, grooved for extra grip. When air is introduced in the channels the central section will expand but as the outer layers resist the expansion the nett result is bending of the arms and a gripping motion. The lifting action is not limited to eggs: for some reason anesthetized mice were included in the research. The Whitesides lab assures us no animals were hurt in the making of the gripper.

* Also see: egg grabbing footage here (.mwv file)
* Also see: Meanwhile in the Whitesides lab