International. The color pixels, developed by a team of scientists led by the University of Cambridge, are compatible with roll-to-roll manufacturing in flexible plastic films, drastically reducing their production cost. The results are reported in the journal Science Advances.
It has been a long-standing dream to imitate octopus or squid skin that changes color, allowing people or objects to disappear into the natural background, but making flexible display screens for large areas remains prohibitively expensive because they are built with high-precision layers multiple
In the center of the pixels developed by Cambridge scientists there is a small gold particle about one billionth of a meter in diameter. The grain sits on a reflective surface, trapping light in the interspace. Around each grain there is a thin, adhesive layer that changes chemically when it is changed electrically, which causes the pixel to change color throughout the spectrum.
The team of scientists, from different disciplines, including physics, chemistry and manufacturing, created the pixels by coating golden grain vats with an active polymer called polyaniline and then spraying them on flexible, mirror-coated plastic, to drastically reduce the cost of production .
The pixels are the smallest that have been created, a million times smaller than the typical pixels of smartphones. They can be seen in sunlight and, because they do not need constant power to maintain their established color, they have an energy efficiency that makes large areas feasible and sustainable. "We started by washing them on aluminized food packages, but then we discovered that aerosol spraying is faster," said co-author Hyeon-Ho Jeong of Cavendish Laboratory in Cambridge.
"These are not the normal tools of nanotechnology, but this kind of radical approach is needed to make sustainable technologies feasible," said Professor Jeremy J Baumberg of the Nanophotonics Center at Cavendish Laboratory in Cambridge, who led the research. "The strange physics of light on the nanoscale allows it to be changed, even if less than a tenth of the film is covered with our active pixels. That's because the apparent size of each pixel for light is many times larger than its physical area when these resonant gold architectures are used. "
The pixels could allow a lot of new application possibilities, such as display screens the size of a building, architecture that can turn off the solar heat load, clothes and active camouflage coatings, as well as small indicators for the next Internet devices of things.
The team is currently working to improve the range of colors and is looking for partners to further develop the technology.
The research is funded as part of an investment by the Engineering and Physical Sciences Research Council of the United Kingdom (EPSRC) at the Cambridge NanoPhotonics Center, as well as the European Research Council (ERC) and the Council. of Scholarships of China.