Engineers develop a stretchable, foldable transparent electronic display (w/ Video)

Sep 23, 2013 by Matthew Chin
Photographs of a stretchable OLED (original emission area: 5.0 mm × 4.5 mm) at specified strains (up to 120%).

(Phys.org) —Imagine an electronic display nearly as clear as a window, or a curtain that illuminates a room, or a smartphone screen that doubles in size, stretching like rubber. Now imagine all of these being made from the same material.

Researchers from UCLA's Henry Samueli School of Engineering and Applied Science have developed a transparent, elastic organic light-emitting device, or OLED, that could one day make all these possible. The OLED can be repeatedly stretched, folded and twisted at room temperature while still remaining lit and retaining its original shape.

OLED technology is used today in screens for many smartphones and some televisions. The new ultra-stretchable OLED material developed at UCLA could lead to foldable and expandable screens for new classes of smartphones and other ; electronics-integrated clothing; wallpaper-like lighting; new minimally invasive medical tools; and many other applications.

"Our new material is the building block for fully stretchable electronics for consumer devices," said Qibing Pei, a UCLA professor of and principal investigator on the research. "Along with the development of stretchable , we believe that fully stretchable interactive OLED displays that are as thin as wallpaper will be achieved in the near future. And this will give creative electronics designers new dimensions to exploit."

This video is not supported by your browser at this time.

The research is published online in the peer-reviewed journal Nature Photonics. The lead author of the study is Jiajie Liang, a postdoctoral scholar in Pei's Soft Materials Research Laboratory at UCLA.

The researchers stretched and restretched the OLED 1,000 times, extending it 30 percent beyond its original shape and size, and it still continued to work at a . In another test to determine the material's maximum stretch, the researchers found it could be stretched to more than twice its original size while still functioning. In addition, it can be folded 180 degrees and can be twisted in multiple directions.

The material has a single layer of an electro-luminescent polymer blend sandwiched between a pair of new transparent elastic composite electrodes. These electrodes are made of a network of silver nanowires inlaid into a rubbery polymer, which allows the device to be used at room temperatures. All of these layers are fully stretchable, foldable and twistable. The new material can also be fabricated in a relatively simple all-solution–based process.

Schematic (left) and top-view (right) illustrations of an encapsulated fully stretchable OLED display comprising 5×5 pixels.

"The lack of suitable elastic transparent electrodes is one of the major obstacles to the fabrication of stretchable display," Liang said. "Our new transparent, elastic composite electrode has high visual transparency, good surface electrical conductivity, high stretchability and high surface smoothness—all features essential to the fabrication of the stretchable OLED."

Images of a stretchable OLED (original emission area: 3.0 mm × 7.0 mm) wrapped around the edge of a 400 µm thick cardboard paper.

The team also demonstrated this ultra-flexible OLED could contain multiple pixels, rather than just a solid block of light. This could pave the way for electronic displays comprising many thousands of pixels. They accomplished this by assembling the silver nanowire–based electrodes into a cross-hatched pattern, with one layer of columns and one layer of rows.

"While we perceive a bright future where information and lighting are provided in various thin, stretchable or conformable form factors, or are invisible when not needed, there are still major technical challenges," Pei said. "This includes how to seal these materials that are otherwise sensitive to air. Researchers around the world are racing the clock tackling the obstacles. We are confident that we will get there and introduce a number of cool products along the way."

Images of an encapsulated OLED (d) is stretched, bent and wrapped around a finger.

Pei is also a member of the California NanoSystems Institute (CNSI) at UCLA.

Explore further: Understanding interface properties of graphene paves way for new applications

More information: www.nature.com/nphoton/journal… photon.2013.242.html

Related Stories

UCLA engineers create fully stretchable OLED

Aug 27, 2011

(PhysOrg.com) -- Engineers at the University of California, Los Angeles, have created the first fully stretchable organic light-emitting diode (OLED). The researchers devised a way of creating a carbon nanotube ...

Recommended for you

'Comb on a chip' powers new atomic clock design

Jul 22, 2014

Researchers from the National Institute of Standards and Technology (NIST) and California Institute of Technology (Caltech) have demonstrated a new design for an atomic clock that is based on a chip-scale ...

Creating optical cables out of thin air

Jul 22, 2014

Imagine being able to instantaneously run an optical cable or fiber to any point on earth, or even into space. That's what Howard Milchberg, professor of physics and electrical and computer engineering at ...

User comments : 4

Adjust slider to filter visible comments by rank

Display comments: newest first

Restrider
2.3 / 5 (3) Sep 24, 2013
This is the next step to the self-updating newspaper seen in Minority Report.
alfie_null
5 / 5 (1) Sep 24, 2013
I'm always curious, when I read of technology like this, as to the expected cost. Will this be something we can casually paper the walls with, or will we see it only in small, expensive devices?
CapitalismPrevails
3 / 5 (2) Sep 24, 2013
This is the next step to the self-updating newspaper seen in Minority Report.

This is the next step in smart watch technology. It kind of reminds me of the rollable poloroid device Val Kilmer used on Red Planet.
hemitite
1 / 5 (1) Sep 24, 2013
Electronic chewing gum?