June 8, 2006

New Sensors Afford Robots a Light Touch

WASHINGTON -- A new type of sensor may give robots a truly light touch -- using electricity and tiny particles to allow a machine to "feel" surfaces, researchers reported on Thursday.

They said their device gave a robot tactile sensitivity equivalent to that of human fingers, and said one early use might be in minimally invasive surgery.

Vivek Maheshwari and Ravi Saraf of the University of Nebraska in Lincoln said their electroluminescent film glowed in response to an applied force.

A specialized camera captures this light and translates it into a picture that is the equivalent of touching and feeling an object.

To illustrate, Maheshwari and Saraf pressed coins against the device. A U.S. penny produced an image detailed enough to show the wrinkles in the clothing of Abraham Lincoln, who is pictured on the coin, and the letters "TY" in "LIBERTY," they report in Friday's issue of the journal Science.

The hope is to coat a robot's "hands" with a film like this, and use the resulting signals to help guide the device.

Surgeons now use their sense of touch to find tumors or gallstones, the researchers wrote.

"Moreover, there is great interest in developing humanoid robots that can sense shapes, textures, and hardness and manipulate complex objects, which are not readily possible by vision alone," they wrote.

Maheshwari and Saraf's film is made of alternating layers of gold and semiconducting cadmium-sulfur nanoparticles separated by nonconducting, or dielectric, films. Nanoparticles are extremely tiny, a nanometer, or a billionth of a meter, or less in diameter.