Electronic paper displays full colour spectrum
Image credit: Mats Tiborn
Swedish researchers have developed a new type of electronic paper that shows all colours that an LED display can provide while drawing ten times less energy than a Kindle tablet.
Developed by a team from Swedish Chalmers University of Technology, the electronic paper made of conductive polymers deposited on a nanostructured surface is less than one micrometre thin, bendable and, unlike current LED displays, provides an excellent viewing experience in an intensely illuminated environment.
“The ‘paper’ is similar to the Kindle tablet,” said Chalmers researcher Andreas Dahlin who developed the technology together with PhD student Kunli Xiong. “It isn’t lit up like a standard display, but rather reflects the external light which illuminates it. Therefore it works very well where there is bright light, such as out in the sun.”
The polymer-coated surface essentially controls how light is absorbed and reflected. Electrical signals propagate through the material in a controlled manner, creating images in high resolution.
The team has so far only created a few pixels but believes the technology is promising due to its outstanding energy efficiency.
However, there are drawbacks. To create the electronic paper, the researchers need to use expensive materials such as silver and gold.
“The gold surface is 20 nanometres thick so there is not that much gold in it,” explained Dahlin. “But at present there is a lot of gold wasted in manufacturing it. Either we reduce the waste or we find another way to decrease the manufacturing cost.”
The technology uses the same red-blue-green system that allows creation of all possible colours in other types of electronic displays such as LED.
Once they manage to cover larger surfaces with the conductive polymers, the researchers believe there will be wider opportunities for commercialisation. Super-energy-efficient displays made of this electronic paper could replace outdoor information screens and signs that are not yet electronic.
“We are working at a fundamental level but even so, the step to manufacturing a product out of it shouldn’t be too far away. What we need now are engineers,” Dahlin concluded.
The electronic paper was described in an article in the journal Advanced Materials.