Imagine sitting outside in the sun, reading a digital screen as thin as paper, but seeing the same image quality as if you were indoors. Thanks to research from Chalmers University of Technology, Sweden, it may soon become a reality. A new type of reflective screen ̵
Traditional digital displays use backlighting to illuminate the text or images displayed on them. This is nice indoors, but it is difficult to see such screens in bright sunshine. However, reflective screens try to use the ambient light, mimicking the way our eyes react to natural paper.
“For reflective screens to compete with the energy – intensive digital screens we use today, images and colors must be reproduced with the same high quality. That will be the real breakthrough. Our research now shows how technology can be optimized, making it attractive to commercial use, says Marika Gugole, a doctoral student at the Department of Chemistry and Chemical Engineering at Chalmers University of Technology.
Researchers had previously succeeded in developing an ultra-thin, flexible material that reproduces all the colors an LED screen can display, while requiring only a tenth of the energy that a standard tablet uses.
But in the previous design, the colors of the reflective screen were not shown with optimal quality. Now the new study, published in the journal Nano Letters takes the material a step further. Using a previously studied, porous and nanostructured material, which contains tungsten trioxide, gold and platinum, they tried a new tactic – turning the design in such a way that the colors could be displayed much more accurately on the screen.
Inverts the design for top quality in colors
The inversion of the design represents a major step forward. They placed the component that makes the material electrically conductive under the pixelated nanostructure that reproduces the colors – instead of over it, which was previously the case. This new design means that you look directly at the pixelated surface, and therefore the colors look much clearer.
In addition to minimal energy consumption, reflective screens have other advantages. For example, they are much less tiring for the eyes compared to looking at a regular screen.
To make these reflective screens, certain rare metals such as gold and platinum are required, but because the end product is so thin, the amounts needed are very small. The researchers have high hopes that in the end it will be possible to reduce the quantities needed for production significantly.
“Our main goal when we develop these reflective screens, or electronic paper, as it is sometimes called, is to find sustainable, energy-saving solutions. And in this case, energy consumption is almost zero because we simply use ambient light in the environment,” explains research leader Andreas Dahlin , professor at the Department of Chemistry and Chemical Engineering at Chalmers.
Flexible with a wide range of applications
Reflective screens are already available on some tablets today, but they only display the colors black and white well, which limits their use.
“A large industrial player with the right technical expertise can in principle start developing a product with the new technology within a few months,” says Andreas Dahlin, who envisions a number of additional applications. In addition to smartphones and tablets, it can also be useful for outdoor advertising, offering energy and resource savings compared to both printed posters or moving digital screens.
The technology in Chalmers researchers’ reflective screens is based on the material’s ability to regulate how light is absorbed and reflected. In the current study, tungsten trioxide is the core material, but in previous studies, researchers also used polymers. The material that covers the surface conducts electronic signals throughout the screen and can be patterned to create high-resolution images.
A new look at color screens
Marika Gugole et al., Electrochromic inorganic nanostructures with high chromaticity and superior brightness, Nano Letters (2021). DOI: 10.1021 / acs.nanolett.1c00904
Provided by Chalmers University of Technology
Citation: New electronic paper shows brilliant colors (2021, July 12) retrieved July 12, 2021 from https://phys.org/news/2021-07-electronic-paper-brilliant-colours.html
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