New York: Scientists led by an Indian-origin researcher have developed the world's first full-colour, flexible thin-film reflective display inspired by nature.
Traditional displays like those on a mobile phone require a light source, filters and glass plates.
But animals like chameleons, octopuses and squids are born with thin, flexible, colour-changing displays that don't need a light source - their skin.
"All manmade displays - LCD, LED, CRT - are rigid, brittle and bulky. But you look at an octopus, they can create colour on the skin itself covering a complex body contour, and it's stretchable and flexible," said Professor Debashis Chanda from the University of Central Florida in US, who led the study.
Researchers were able to change the colour on an ultrathin nanostructured surface by applying voltage. The new method doesn't need its own light source. Rather, it reflects the ambient light around it.
A thin liquid crystal layer is sandwiched over a metallic nanostructure shaped like a microscopic egg carton that absorbs some light wavelengths and reflects others.
The colours reflected can be controlled by the voltage applied to the liquid crystal layer.
The interaction between liquid crystal molecules and plasmon waves on the nanostructured metallic surface played the key role in generating the polarisation-independent, full-colour tunable display.
It's a leap ahead of previous research that could produce only a limited colour palette, researchers said.
And the display is only about few microns thick, compared to a 100-micron-thick human hair. Such an ultrathin display can be applied to flexible materials like plastics and synthetic fabrics, they said.
The research has major implications for existing electronics like televisions, computers and mobile devices that have displays considered thin by today's standards but monstrously bulky in comparison.
But the potentially bigger impact could be whole new categories of displays that have never been thought of.
"Your camouflage, your clothing, your fashion items - all of that could change. Why would I need 50 shirts in my closet if I could change the colour and pattern?" Chanda said.
Researchers used a simple and inexpensive nano-imprinting technique that can produce the reflective nanostructured surface over a large area.
"This is a cheap way of making displays on a flexible substrate with full-colour generation," Chanda added.
The research was published in the journal Nature Communications.
