Smarpthones and tablets with flexible, foldable displays could soon be on the way thanks to researchers at UCLA, who have created an oled that can be repeatedly stretched, folded and twisted at room temperature while still retaining its original shape and remaining lit.
"Our new material is the building block for fully stretchable electronics for consumer devices," said Qibing Pei, a UCLA professor of materials science and engineering and principal investigator. "Along with the development of stretchable thin film transistors, 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." In tests, the researchers were able to stretch and re-stretch the oled 1,000 times, and it still continued to work at a high efficiency. They were also able to fold it 180° and twist it in multiple directions. The material has a single layer of an electro-luminescent polymer blend sandwiched between a pair of 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 displaya," said Liang. "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."