Stanford researchers create artificial skin that can feel pressure

Posted by Andru Edwards Categories: Science

Prosthetics have come a long way since the days of wooden legs. Now a team of Stanford researchers says it's taken a big step towards developing an artificial skin that can actually "feel" pressure and could someday help amputees and burn victims.

Spray-on carbon nanotubes and deformable silicone storing an electrical charge form the stretchy, sensitive material that's being billed as a synthetic skin prototype by the team of Stanford researchers led by associate professor of chemical engineering Zhenan Bao that developed it. The flexible, skin-like sensor can be stretched in any direction without tearing, losing its shape, or wrinkling and it's sensitive enough to detect a wide range of pressure.

"This sensor can register pressure ranging from a firm pinch between your thumb and forefinger to twice the pressure exerted by an elephant standing on one foot," Darren Lipomi, a Stanford post-doctoral researcher who helped develop the artificial skin sensor, told PopSci.com.

Lipomi said that the use of carbon nanotubes, a stretchable "conductive spaghetti," gives the material the ability to register not just touch like an iPhone's touchscreen but also measure the pressure of the touch.

Lipomi and two Stanford graduate students, Benjamin Tee and Michael Vosgueritchian, are lead authors of the paper "Skin-Like Pressure and Strain Sensors Based on Transparent Elastic Films of Carbon Nanotubes" published online by Nature Nanotechnology, with Bao, who runs Stanford's "skin lab," a coauthor.

Lipomi and his colleagues created the 8-by-8-inch square of artificial skin by stretching silicone that had been sprayed with nanotubes suspended in liquid (video below). The Stanford team then added a second, perpendicular layer of stretched silicone to enable the material to be stretched in any direction without breaking or deforming.

The initial stretching process causes the nanotubes to act like "little springs" that can be stretched "again and again" without losing conductivity, according to Bao.

A third layer of silicone with an electrical charge sits between the two carbon nanotube layers to measure pressure as the layer's capacitance increases. Bao and her team actually created an even more pressure-sensitive synthetic skin a year ago, according to PopSci.com, but the more recently created material is the first that is transparent.

Lipomi said the development of a working artificial skin could be used in robotics to sheath an android along the lines of the human-like Data character in Star Trek, but that the "ultimate dream" was to "restore sensitivity to lost skin or amputees, injured soldiers, burn victims—that;'s the ultimate goal of this type of science."

This article, written by Damon Poeter, originally appeared on PCMag.com and is republished on Gear Live with the permission of Ziff Davis, Inc.