This Rubbery Artificial 'Skin' Could Give Robots a Sense of Touch

According to a new study conducted by mechanical engineers at the University of Houston,Rubber electronics and sensors that operate normally even when stretched to up to 50 percent of their length could work as artificial skin on robots which will enable them to sense strain, pressure and temperature also can give flexible sensing capabilities to a range of electronic devices, the engineers said.
"It's a piece of rubber, but it has the function of a circuit and sensors," said Cunjiang Yu, an assistant professor of mechanical engineering at the University of Houston. Yu and this research was published online Sept. 8 in the journal Science Advances. A robot — perhaps even a soft, flexible one, with skin that's able to feel its surroundings—could work side by side with humans without endangering them, Yu said.

In the research, Yu and his colleagues used the electronic stretchable skin to sense the temperature of hot and cold water in a cup and also the robot to spell out "YU LAB"  alphabets from computer signals sent to the robotic hand into finger gestures.
Electronics and robots are typically limited by the stiff and rigid semiconductor materials that make up their computer circuits. As such, most electronic devices lack the ability to stretch, the authors said in the study.
Yu and his team made the stretchable material by mixing really small, semiconducting nanowires 1,000 times thinner than a human hair — into a solution of a widely used, silicon-based organic polymer, called polydimethylsiloxane, or PDMS for short.
When dried at 140 degrees Fahrenheit (60 degrees Celsius), the solution hardened into a stretchable material embedded with millions of tiny nanowires that carry electric current.
The researchers applied strips of the material to the fingers of a robotic hand. The electronic skin worked as a sensor that produced different electrical signals when the fingers bent. Bending a finger joint puts strain on the material, and that reduces electric current flow in a way that can be measured.
"This will change the field of stretchable electronics," he said.