A new type of artificial skin with a sense of touch that rivals the human variety could lead to next-generation robotic and prosthetic devices.
When covered with the electronic skin, or "e-skin" as the researchers call it, robots would be able to touch and move objects with the appropriate force. For example, the e-skin would allow the robot to sense the difference between an egg and a frying pan and adjust the force of its grip accordingly.
So far the researchers have made a prototype device and shown that the material can detect a wide range of pressures – 0 to 15 kilopascals, which accounts for typical daily activities.
“There have been a lot of advances in robotics. But one of the issues is the ability to be able to sense an object, and, knowing whether it’s hard or soft, [and] how to be able to grab it,” said lead study researcher Ali Javey, a professor at the University of California at Berkeley.
“If we ever wanted a robot that could unload the dishes, for instance, we'd want to make sure it doesn't break the wine glasses in the process."
Previous attempts to make artificial skin have relied on organic materials, which eat up a lot of power. This means heavy batteries, which isn’t ideal for portable devices, such as robots and prosthetic limbs.
To make their e-skin, Javey and his colleagues used inorganic materials. While typically too brittle to conform to robotic limbs, Javey and his team used tiny wires, called nanowires, of an inorganic material, turning the brittle material into a flexible one.
The team used a printing process to assemble the nanowires into a thin sheet of plastic. The e-skin was then covered with pressure-sensitive rubber pixels. Each pixel is connected to an electronic “switch” made out of hundreds of nanowires. Touching the e-skin causes the rubber to deform, which “flips” the switch of one of the pixels.
The researchers have not yet integrated their e-skin with a computer chip, which would be needed to interpret the information from the electronic switches.
Longer term, the researchers envision the e-skin being used with prosthetic limbs. Instead of a computer chip, however, the electronic skin could interface with the human brain directly.
Javey and his colleagues detail their development online Sept. 12 in Nature Materials.