The sensor can detect differences in hardness, so it has the potential to detect cancer and gallstones. That ability could add a critical component to today's minimally invasive surgeries, Saraf says.
"If you have an endoscopea fiber optic cable [that transmits images from the insides of organs]the surgeon sees the optical image," he said.
But doctors often can't detect, say, tumors and gallstones through sight alone. The new supersensitive sensors could "feel" a patient's insides and transmit the impression as a visual image.
Saraf is working on a project now whereby a doctor could press the sensor onto tissue suspected to contain cancer cells and tell exactly where those cancer cells are. Such precision could reduce the amount of tissue removed in, for example, breast cancer surgery.
"Moreover," the researchers point out in the paper, "there is great interest in developing humanoid robots that can sense shapes, textures, and hardness and manipulate complex objects, [tasks] which are not readily possible by vision alone."
Saraf said the new technology is reasonably cheap, costing 50 cents to a dollar (U.S.) per square inch to produce. It can be made in sheets of up to a meter, or about three feet, square.
Lukas Lichtensteiger is a postdoctoral fellow at Harvard University's Department of Chemistry and Chemical Biology in Cambridge, Massachusetts.
He works on self-assembling micro-robotic systems, which involve components that come together without human interference.
In nature, this type of activity occurs when proteins form and when DNA replicates. In the lab similar processes can be used to create materials that heal themselves when heated, among other feats.
Lichtensteiger called the work by Maheshwari and Saraf "a very elegant new approach."
"I expect that we will soon see self-assembling nanostructures as integral parts in many other robotic sensors and actuators," he said.
In a related Perspectives piece in the same issue of Science, engineer Richard Crowder of the United Kingdom's University of Southampton agrees that the new sensor shows great promise for medicine and robotics.
"However, as with most sensors of this resolution and size, the challenge is to extract the sensor's information efficientlysomething the nervous system does with supreme efficiency," he wrote, adding that repeated trials will reveal the accuracy of the new sensor.
Study co-author Saraf said the next direction he wants to go in is temperature imaging.
"If I could image temperature at the same resolution, I could build infrared cameras a hundred times better than we have today," he said. He adds that this could improve technologies such as night vision and cameras on space telescopes.
Free Email News Updates
Best Online Newsletter, 2006 Codie Awards
Sign up for our Inside National Geographic newsletter. Every two weeks we'll send you our top stories and pictures (see sample).
SOURCES AND RELATED WEB SITES