Stretchable Polymer Material Lights Up

In the near future, real estate agents will point out features in a home that they are trying to sell, such as an entire wall that can be illuminated or a computer display on flat surfaces, such as a refrigerator or window.

These innovations, including wrapping electronic diplays around curved objects, have been developed by researchers at UCLA’s Henry Samueli School of Engineering and Applied Science. The transparent, elastic organic light-emitting device, or OLED, has a polymer component so that it can be stretched, folded, or twisted at room temperature while still remaining lit, according to the university’s press release.

“Our new material is the building block for fully stretchable electronics for consumer devices,” says Qibing Pei, a UCLA professor of materials science and engineering and principal investigator on the research. “Along with the development of stretchable thin-film flexible imagetransistors, 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.”

The material can give rise to new classes of smartphones and other electronic devices, such as wallpaper-like lighting and new minimally invasive medical devices. The researchers’ paper is published in the journal Nature Photonics.

In tests, the researchers stretched the OLED (note: some call it a polymer light-emitting electrochemical cell, or LEC) 1,000 times, up to 30 times its original shape and size, and it still worked efficiently, the researchers say. In other tests, the scientists folded the material 180 degrees and twisted it in multiple directions.

Polymers played a role in its creation. The UCLA press release explains how it was made:

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.

“The lack of suitable elastic transparent electrodes is one of the major obstacles to the fabrication of stretchable display,” Liang says. “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.”

Complicated polymer materials are no match for the technicians at Polymer Solutions. Often, contamination creeps into the manufacturing process of a product or material made with polymers. But the technicians can determine what the contamination is or how a product fails to live up to its performance standards.

Source: “UCLA engineers develop a stretchable, foldable transparent electronic display,” UCLA, 9/23/13
Source: “UCLA Engineers develop flexible and stretchable LEDs,” YouTube
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