Discover Magazine, The Year in Science 2006:

#95 Technology: Machines Learn How to Feel.
by Richard Morgan

Engineers at the University of Nebraska reported in June that they had developed a way to give robots a sense of touch: electronic skin that is cheap, flexible, and twice as sensitive as a human fingertip. This sensitivity comes from a film made of alternating monolayer of gold and cadmium sulfide nanoparticles separated from each other by a very thin polymer film. Any pressure against the electronic skin increases conductivity through the film.

Artifical skin could help robots grab fine objects, like Mars rocks. Another use, says researcher Ravi Saraf, is a probe that could sense cancerous tissue inside a patient. To test the skin's medical applications, Saraf says, "We just went to the butcher shop and started buying livers and muscles," If the concept works, biopsies may one day be replaced by a tiny mechanical caress.