From building facades in San Diego to road signs in Australia, electronic paper has surpassed Kindle into our daily lives in some very interesting applications. The scientific team of the Swedish University of Science and Technology is working hard to expand the application range of electronic paper technology, providing a complete set of accurate and bright colors through the inverted new design.



E-readers represented by Kindle do not require a backlight to illuminate text and images, so their power consumption is much lower than that of smartphones and tablets. The feature of these e-readers is the use of reflective screens made of conductive polymers that reflect and absorb ambient light, imitating the way our eyes process information on ordinary paper.



This makes the display use the least energy, easier for the eyes, and can be processed into a thin or even flexible form. However, one aspect of this technology has proven to be challenging, and that is to produce electronic paper with full-color displays, or at least the same quality as we use on tablets and mobile phones.



In 2016, the team proposed a flexible full-color electronic paper with a thickness of less than 1 micron and energy consumption only one-tenth of Kindle. This display technology is characterized by laying conductive components on a pixelated surface and using a combination of red, green, and blue pixels to produce different colors, although the quality is not ideal.

To solve this problem, scientists used a new porous material composed of nitrous oxide, gold and platinum, and used it as a conductive component. This material is laid under the pixelated surface, instead of laying on it as before, which means that the user directly looks at the pixel and can get a clearer color display. Therefore, the team said that this new display is significantly better than the latest commercial e-readers in terms of color and brightness.



Marika Gugol, a doctoral student at Chalmers University of Technology, said: “For reflective screens to compete with the energy-intensive digital screens we use today, images and colors must be reproduced at the same high quality. This will be A real breakthrough. Our research now shows how to optimize the technology to make it attractive for commercial use."



One direction the team hopes to improve is the use of rare metals, in this case gold and platinum. Because the display is very thin, it only requires a small amount of these materials, but scientists hope to continue to refine the design so that these materials are needed less and less. They said that this technology could one day be used in mobile phones, tablet computers and outdoor billboard displays, and envisaged that it might be commercialized as soon as possible in the hands of the right people.



Andreas Dahlin, the author of the research report, said: "In principle, a large industrial enterprise with appropriate technical capabilities can start to develop a product that uses a new technology within a few months."