Producing an artificial skin touch help overcome a major challenge in robotics: control the amount of force required to hold and manipulate a wide range d. A group of researchers at the University of California at Berkeley, USA, managed to produce a pressure-sensitive electronic material from semiconductor nanowires. The achievement paves the way for the development of a new type of artificial skin. "The idea is to make the material has features similar to human skin, which means incorporating the ability to touch and feel objects," says Ali Javey, a professor of electrical engineering and computer science who led the team, whose results were published on Sunday (12 / 9) in the journal Nature Materials. The material, called e-skin ("electronic skin") by its creators, is the first made from crystalline inorganic semiconductors. Producing an artificial skin touch help overcome a major challenge in robotics: control the amount of force needed to hold and handle a wide range of objects. "Humans know how to hold a fragile egg without breaking it. If we want a robot do it, or wash the dishes, for example, need to make sure he does not break the glasses of wine in the process. But we also want the the same robot to be able to firmly hold a kettle drum without dropping it, "Javey said. A more distant goal is to use the e-skin to restore the sense of touch in patients who need prosthetic limbs. These new dentures would require significant advances in the integration of electronic sensors in the human nervous system. "But the problem is that the materials are not good organic semiconductors, which means that electronic devices made with them will often need high-voltage circuits for their work," Javey said. According to him, inorganic materials such as silicon, on the other hand, have excellent electrical properties and can operate with little energy. They are also chemically stable. "But historically, these materials have been inflexible and easy to break," he said. "In this respect, the work of several research groups, including ours, have recently shown that tiny wires or tapes of inorganic materials can be made to be highly flexible, that is ideal for electronic sensors and high-performance," he said. The Californian group used a new manufacturing technique. Initially, the scientists implanted wires with nanometric thickness (billionths of a meter) in a cylindrical drum. Then the drum was rolled into a sticky substrate. The substrate used was a polymer film, but researchers say the technique works with various materials such as plastics, paper or glass. As the drums rolled, the nanowires were deposited on the substrate in an orderly fashion, forming the basis from which thin, flexible sheets of electronic materials can be built. The researchers printed the nanowires in a square matrix with 18 by 19 pixels, measuring 7 cm on each side. Each pixel contains a transistor made of hundreds of semiconductor nanowires. The transistors were integrated under a rubber pressure-sensitive, so if you enter a sensory function. The matrix required less than 5 volts of electricity to run and kept his income after undergoing tests to more than 2000 cycles of folds. According to the authors of the study, skin-and was able to detect pressures from 0 to 15 kilopascals, a change comparable to the force used for everyday activities like typing on a computer keyboard or hold an object. . . .