UCLA engineers create fully stretchable OLED

Aug 27, 2011 by Nancy Owano weblog
Image: Wiley

(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 and polymer electrode and layering it onto a stretchable light-emitting plastic. Their device is a two-centimeter square with a one-centimeter square area that gives off a blue light. Details of their work were published in July in Advanced Materials. The paper is titled, "Intrinsically Stretchable Polymer Light-Emitting Devices Using Carbon Nanotube-Polymer Composite Electrodes."

The method they used for their proof-of-concept device has attracted interest because stretchable electronics is peppered with lots of design challenges, starting with carbon nanotubes themselves. These nanotubes are stretchable and are conductive, but to keep their shape, they need to be attached to some surface. Researchers have found that coating carbon nanotubes onto a plastic backing has not worked well, because the nanotubes slide off or past each other instead of stretching with the elastic. Until the UCLA team’s work, researchers were unable to come up with an entirely stretchable .

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Researchers at UCLA demonstrate their fully stretchable OLED. They achieved the feat by sandwiching a carbon nanotube-polymer blend on either side of a light-emitting plastic.

Another drawback encountered has been that the film is rough and can cause shorting, says Zhenan Bao, a Stanford professor of chemical engineering who works on stretchable solar cells. "Using this method, they ended up with a relatively flat surface that can be used for an ."

Nonetheless, the need for further work in this area is far from over. She said that stretchable electronics demonstrated thus far lose conductivity after being stretched too far or too many times, so more research is needed. "We are still some ways off from having high-performance, really robust, intrinsically stretchable devices," says Bao, but "with this work and those from others, we are getting closer and closer to realizing this kind of sophisticated and multifunctional electronic skin."

According to Technology Review, could enter our worlds in the form of video displays that could be rolled up and tucked into a shirt pocket, or cell phones that could swell or shrink. In medical science, one might see electronic sheets draped like cloth.

Explore further: Understanding the source of extra-large capacities in promising Li-ion battery electrodes

More information: Intrinsically Stretchable Polymer Light-Emitting Devices Using Carbon Nanotube-Polymer Composite Electrodes, Advanced Materials, DOI:10.1002/adma.201101986

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Expiorer
5 / 5 (1) Aug 28, 2011
in video it seems to bee not stretchable
Tomator
not rated yet Aug 28, 2011
in video it seems to bee not stretchable

It is. A bit.
The video is short, however, becouse - I thinh - the oled stopped shining at this point.
hyongx
not rated yet Aug 28, 2011
It stretches. It proves the concept. The article in AdvMat says that it can be stretched linearly up to 45% strain. The video is far enough away from the OLED that 45% strain is harder to see.
There is nothing in the video to indicate that it stopped shining after this stretching. I think this is a super cool Sci/Eng development.