London: Robots are soon going to get so sensitive to touch that they would even be able to feel the tickle of fly feet—thanks to Stanford scientists who have developed a sensor for artificial skin to be used on prosthetic limbs or robots.
By sandwiching a precisely moulded, highly elastic rubber layer between two parallel electrodes, the team created an electronic sensor that can detect the slightest touch.
"It detects pressures well below the pressure exerted by a 20 milligram bluebottle fly carcass we experimented with, and does so with unprecedented speed," Nature quoted Zhenan Bao, an associate professor of chemical engineering who led the research, as saying.
The key innovation in the new sensor is the use of a thin film of rubber moulded into a grid of tiny pyramids, said Bao.
Previous attempts at building a sensor of this type using a smooth film encountered problems.
"The microstructuring we developed makes the rubber behave more like an ideal spring," Mannsfeld said.
The total thickness of the artificial skin, including the rubber layer and both electrodes, is less than one millimeter.
The speed of compression and rebound of the rubber is critical for the sensor to be able to detect – and distinguish between – separate touches in quick succession.
The thin rubber film between the two electrodes stores electrical charges, much like a battery.
When pressure is exerted on the sensor, the rubber film compresses, which changes the amount of electrical charges the film can store.
That change is detected by the electrodes and is what enables the sensor to transmit what it is "feeling."
This degree of sensitivity could make the sensors useful in a broad range of medical applications, including robotic surgery, Bao said.
In addition, using bandages equipped with the sensors could aid in healing of wounds and incisions. Doctors could use data from the sensors to be sure the bandages were not too tight.
Automobile safety could also be enhanced.
The study has been published online by Nature Materials. (ANI)