Electronic displays are usually made of glass, because that’s the only material strong enough to protect the delicate electronics of a touch screen. But now there’s a display technology that allows a screen to be stretched and folded, while still keeping the electronics inside safe and working.
It’s a transparent, elastic organic light-emitting device, or OLED, developed by researchers from UCLA led by Qibing Pei, a materials scientist. OLEDs are common in many devices, but they typically aren’t stretchable. And while there are a number of designs for stretchable electronics, none are transparent.
A transparent display that bends could usher in smartphone screens that have adjustable sizes, displays that double as window shades and medical implants and flex with a person’s body.
To make the OLED, the researchers worked in layers. The top layer is a protective cover. Next is a transparent electrode, and underneath that is a polymer that lights up when an electrical current his it. Underneath that polymer is another transparent electrode, followed by another cover. The electrodes are made of a network of silver nanometer-thick wires inlaid into a stretchy polymer. The network of wires makes a crosshatch pattern. Each point where the wires cross lights up, making a pixel.
Pei’s team tested the OLED by stretching it out more than 1,000 times. The OLED could be pulled to twice its original length and remain illuminated.
There are still some technical challenges. One is that the material is sensitive to air, so there has to be a way to seal it in the same way current glass displays shield their sensitive components. But that’s doable, Ping said in a press release.
The research appears in the current issue of the journal Nature Photonics.
Credit: UCLA / YouTube