The robotic microhand, made of silicon finger bones and plastic balloon joints, when clenched is about as thick as a dime.

A microscopic robot hand, made of silicon and plastic balloons, could help perform surgery and defuse bombs.

The "microhand" is so tiny that when clenched into a fist it measures a little over one millimeter across, or roughly as thick as a dime [image]. It is made using silicon finger bones and balloons for joints that inflate and deflate to flex the fingers.

The robot hand was designed by microelectromechanical systems scientist Yen-Wen Lu at Rutgers University in Piscataway, N.J., and mechanical engineer Chang-Jin Kim at UCLA. The prototype has four fingers arranged into a cross, each digit roughly a half-millimeter long, made via conventional semiconductor manufacturing techniques normally used to assemble electronics.

The microhand is gentle but strong enough to pluck a single delicate fish egg from a sticky egg mass [video].

"You could imagine this being used for microsurgery— at the end of a catheter, for instance. We found we could grab a nerve bundle with it," Kim told LiveScience. "We are also working with a company who said this could help disarm explosives. Right now the robotic manipulators used there are pretty crude, and a gentle and dexterous hand would be helpful."

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