- The smallest pixel ever created can be used to build massive screen, large enough to cover whole buildings.
- These pixels are a million times smaller than those in modern cell phones.
In recent decades, plasmonic metasurfaces have emerged as a valuable tool supporting a broad range of enhanced optical phenomena, leading to applications like actuation, imaging, sensing, and flat panel display.
Display applications, in particular, are capable of generating a complete color gamut and high spatial resolution, and this has been made possible by recent advances in nanolithography. However, it’s very difficult to quickly tune plasmonic coloration and it requires complex lithographic methods that cost a lot.
Now researchers at the University of Cambridge have developed color pixels that can be fabricated on flexible plastic films in an inexpensive way. These are the smallest pixels ever created and they can be used to build massive flexible screens that can cover whole buildings.
How They Created Such Tiny Pixels?
For years, scientists all over the world have been trying to develop material capable of mimicking the color-changing skin of squid or octopus, enabling objects to blend into the background. Also, they haven’t been able to bring down the manufacturing cost of large flexible screens because they require extremely precise multiple layers.
In this work, researchers were able to create a million times smaller pixels than those in modern cell phones. To do this, they trapped light particles under tiny grains of gold.
This tiny gold particle (of nanometer scale) is placed on top of a reflective surface so that it can trap the light in between the gaps. A thin sticky coating is applied around every single gold particle. The chemical properties of this coating can be altered by switching currents, which ultimately changes the color of the pixel across the spectrum.
In order to create such a tiny pixel, researchers from different fields such as chemistry, physics, and manufacturing coated vats of golden particles with a conducting polymer named polyaniline and sprayed them onto pliable plastic (coated with mirror). This significantly reduced production cost.
These pixels are visible during the bright day and since they don’t require constant energy to retain their color, they can be efficiently used in large areas.
This kind of radical method can make sustainable technologies practical. At nanometric scale, the unusual laws of physics of light allow it to be controlled, even if 1/10th of the film is coated with active pixels. This happens due to the larger size of the individual pixels than their physical areas in vibrant gold architectures.
These pixels can have tons of future applications, including customized solar heat load architectures, active camouflage coating and clothing, massive display screens and upcoming IOT devices.
The researchers are now trying to improve the color range and collaborate with other companies/organizations to further develop this technology.