The first ever user-interactive sensor network on flexible plastic — a new milestone in the field of robotics — was recently created by researchers at UC Berkeley. The new electronic skin, or e-skin, reacts to touch by lighting up — the harder that the pressure that is applied is, the brighter the light shines.
“We are not just making devices; we are building systems,” stated Ali Javey, UC Berkeley associate professor of electrical engineering and computer sciences, who’s also a faculty scientist at the Lawrence Berkeley National Laboratory. “With the interactive e-skin, we have demonstrated an elegant system on plastic that can be wrapped around different objects to enable a new form of human-machine interfacing.”
This new e-skin builds on earlier research that utilized semiconductor nanowire transistors that were layered on top of thin rubber sheets to create a sensor network.
As well as improving the sensory information available to robots with regard to physical ‘touch’, the researchers think that the new e-skin technology could be applied to the creation of other technologies, such as wallpaper/touchscreen display hybrids, and “dashboard laminates that allow drivers to adjust electronic controls with the wave of a hand.”
“I could also imagine an e-skin bandage applied to an arm as a health monitor that continuously checks blood pressure and pulse rates,” stated study co-author Chuan Wang, who conducted the work as a post-doctoral researcher in Javey’s lab at UC Berkeley.
UC Berkeley continues:
The experimental samples of the latest e-skin measure 16-by-16 pixels. Within each pixel sits a transistor, an organic LED and a pressure sensor.
To create the pliable e-skin, the engineers cured a thin layer of polymer on top of a silicon wafer. Once the plastic hardened, they could run the material through fabrication tools already in use in the semiconductor industry to layer on the electronic components. After the electronics were stacked, they simply peeled off the plastic from the silicon base, leaving a freestanding film with a sensor network embedded in it.
“Integrating sensors into a network is not new, but converting the data obtained into something interactive is the breakthrough,” stated Wang, now an assistant professor of electrical and computer engineering at Michigan State University. “And unlike the stiff touchscreens on iPhones, computer monitors and ATMs, the e-skin is flexible and can be easily laminated on any surface.”
“The electronic components are all vertically integrated, which is a fairly sophisticated system to put onto a relatively cheap piece of plastic,” explained Javey. “What makes this technology potentially easy to commercialize is that the process meshes well with existing semiconductor machinery.”
The researchers are now working on altering the e-skin sensors to respond to temperature and light as well as pressure.
The new research was just published online in the journal Nature Materials.