23.09.14

Scientists look to squids for LCD tech breakthrough

Colour-changing squid skin could be the key to a new generation of LCDs after a research team created a full-colour display technology that uses aluminium nanoparticles to create vivid red, blue and green hues. The technology, unveiled by Rice University's Laboratory for Nanophotonics (LANP), would replace coloured dyes, which are currently found in most commercial displays and suffer from fading and bleaching from sun exposure.

The display breakthrough was achieved as part of the LANP’s quest to create artificial squid skin. Squids can camouflage themselves by changing their skin colour to their environment.

Naomi Halas, director of LANP, said: “Our goal is to learn from these amazing animals so that we could create new materials with the same kind of distributed light-sensing and processing abilities that they appear to have in their skins.

“We know cephalopods have some of the same proteins in their skin that we have in our retinas, so part of our challenge, as engineers, is to build a material that can ‘see’ light the way their skin sees it, and another challenge is designing systems that can react and display vivid camouflage patterns.”

The new display technology delivers bright red, blue and green hues from five-micron-square pixels that each contains several hundred aluminium nanorods. By varying the length of the nanorods and the spacing between them, LANP researchers Stephan Link and Jana Olson showed they could create pixels that produced many colours.

Link, associate professor of chemistry at Rice and the lead researcher on the PNAS study, said: “Aluminium is useful because it’s compatible with microelectronic production methods, but until now the tones produced by plasmonic aluminium nanorods have been muted and washed out. The key advancement here was to place the nanorods in an ordered array.”

He continued: “Because the nanorods in each array are aligned in the same direction, our pixels produce polarised light,” he said. “This means we can do away with one polariser in our setup, and it also gives us an extra knob that we can use to tune the output from these arrays. It could be useful in a number of ways.”

Halas said eventually the team hoped to combine a number of technologies to create a material that can sense light in full colour and react with full-colour camouflage displays.

The research was funded by the Department of Defense through the Office of Naval Research’s Basic Research Challenge program and by the Welch Foundation. Co-authors of the colour display study in PNAS include Lifei Liu, Wei-Shun Chang, Benjamin Foerster, Nicholas King and Mark Knight, all of Rice.