The Robotic Touch

We're used to thinking of the most sophisticated robots of the future as being like C3PO from the "Star Wars" movies—all glittering metal on the outside. But what if they had a kind of "skin" that mimicked our own, enabling them to feel subtle surfaces and judge their composition? They may soon have this distinctly organic characteristic. In today's issue of Science, Vivek Maheshwari and Ravi F. Saraf of the Department of Chemical Engineering of the University of Nebraska at Lincoln report on their invention of a tactile sensor that could prove to be a significant breakthrough in robotics and other fields, such as medicine.

According to an item in Nature, Saraf came up with the novel idea in response to the loss of a close friend to breast cancer. He wanted to invent a sensor to help doctors diagnose the disease at an earlier stage by detecting smaller malignant growths. The Nebraska team is working with the Edward Via Virginia College of Osteopathic Medicine, Blacksburg, Va., on medical applications for the new sensor. However, it is the notion of covering portions of a robot's exterior, particularly its "hands," with the technology that is making headlines in the technical community.

The new sensor is a thin-film device about 100 nanometers thick built in alternating layers of gold and cadmium sulphide nanoparticles separated by insulating polymer sheets just 2 or 3 nanometers thick. When a current is passed through the film, it can detect pressure by corresponding changes in the current and the resulting electroluminescent light intensity of the cadmium sulphide particles in the film. Using a charge-coupled device, this information can be displayed as an image. The sensor can detect surface details to within a pressure of approximately 10 kilopascals and distinguish features as small as 40 micrometers wide—the lateral and height resolutions of texture comparable to the human finger's at similar stress levels.

A roboticist said of the development, "Incorporation of this sensor into robotic hands may substantially improve their dexterity." Richard Crowder of the School of Electronics and Computer Science at the University of Southampton, Southampton, England, wrote in a commentary: "It's another tool in the armory... And it came out of left field."

Graciously inspired, from left field or any field, this is one new development that should be fully grasped and appreciated—and not just by robots.


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