Aaron Dollar, an assistant professor of mechanical engineering at Yale, has invented a robot with a soft touch. His plastic hand is deft enough to grasp a wide variety of objects without damaging them. What's more, it's cheaper and requires less processing power than the metal hands typically used in robots.

Dollar's design uses plastic fingers that can lightly brush against an object--whether it's a wine glass, beach ball, or telephone--before firming up their grip. Few researchers have used soft plastic in robotics before, partly because it can be difficult to shape small, precise parts out of such materials. To get around this problem, Dollar mills wax molds for each finger. He places sensors and cables in the molds and then pours in layers of three types of plastic with varying degrees of softness--for fingers, joints, and finger pads. Once the plastics harden and are removed from the molds, the fingers are ready to be hooked up to a base. Dollar's design has already been licensed to one robotics manufacturer, and because it replicates the flexibility and gentleness of a human hand, he is investigating whether it could work as a prosthetic.--Kristina Grifantini