The microelectromechanical systems scientist Yen-Wen Lu at Rutgers University in Piscataway, N.J., and mechanical engineer Chang-Jin Kim at the University of California has designed a microscopic robot hand.

The hand is so tiny that when clenched into a fist it measures only a little over 1 millimeter or roughly equal to the thickness of a dime. It is made up of silicon finger bones and balloons for joint that inflates and deflates to flex fingers.

The inventors are sighting usages in defusing bombs and in performing micro-surgery. They found out that they could grab a nerve bundle with it. The hand is gentle enough to pluck a single delicate fish egg from a sticky egg mass.

Lu and Kim reported their findings online Oct. 16 via the journal Applied Physics Letters.