Gadgets

Researchers develop colour-changing artificial chameleon skin

ANI | August 22, 2019 03:23 PM
The researchers also observed that the artificial cells can 'swim' in simple ways, similar to the algae Volvox.

Washington D.C. [USA], Aug 22 (ANI): Researchers have developed artificial chameleon skin that changes its colour when exposed to light.

The material, developed by researchers from the University of Cambridge, is made up of tiny particles of gold-coated in a polymer shell, and then squeezed into microdroplets of water in oil.

When exposed to heat or light, the particles stick together, changing the colour of the material. The results are reported in the journal -- Advanced Optical Materials.

In nature, animals such as chameleons and cuttlefish are able to change their colour thanks to chromatophores: skin cells with contractile fibers that move pigments around.

The pigments are spread out to show their colour or squeezed together to make the cell clear.

The artificial chromatophores developed by the researchers are built on the same principle, but instead of contractile fibers, their colour-changing abilities rely on light-powered nano-mechanisms, and the 'cells' are microscopic drops of water.

When the material is heated above 32-degree centigrade, the nanoparticles store large amounts of elastic energy in a fraction of a second as the polymer coatings expel all the water and collapse.

This has the effect of forcing the nanoparticles to bind together into tight clusters. When the material is cooled, the polymers take on water and expand, and the gold nanoparticles are strongly and quickly pushed apart, like a spring.

"Loading the nanoparticles into the microdroplets allows us to control the shape and size of the clusters, giving us dramatic colour changes," said Dr Andrew Salmon from Cambridge's Cavendish Laboratory, the study's co-first author.

The geometry of the nanoparticles when they bind into clusters determines which colour they appear as: when the nanoparticles are spread apart they are red and when they cluster together they are dark blue.

However, the droplets of water also compress the particle clusters, causing them to shadow each other and make the clustered state nearly transparent.

At the moment, the material developed by the Cambridge researchers is in a single layer, so is only able to change to a single colour.

However, different nanoparticle materials and shapes could be used in extra layers to make a fully dynamic material like real chameleon skin.

The researchers also observed that the artificial cells can 'swim' in simple ways, similar to the algae Volvox. Shining a light on one edge of the droplets causes the surface to peel towards the light, pushing it forward.

Under stronger illumination, high pressure bubbles briefly form to push the droplets along a surface.

"This work is a big advance in using nanoscale technology to do biomimicry. We're now working to replicate this on roll-to-roll films so that we can make metres of colour changing sheets. Using structured light we also plan to use the light-triggered swimming to 'herd' droplets. It will be really exciting to see what collective behaviours are generated," said co-author Sean Cormier. (ANI)

Have something to say? Post your comment
Must Read
166 beneficiaries avail facility during MGSVY camp at Rajowal village
166 beneficiaries avail facility during MGSVY camp at Rajowal village
DC directs AAI and PWD to conduct joint survey for ensuring easy access to passengers for airport from Adampur
DC directs AAI and PWD to conduct joint survey for ensuring easy access to passengers for airport from Adampur
I dare majithia to show even a single development centric work done in Dera Baba Nanak during decade long SAD rule: Randhawa
I dare majithia to show even a single development centric work done in Dera Baba Nanak during decade long SAD rule: Randhawa
AirAsia's Bhubaneswar-Bangkok service to be temporarily suspended from Sept 25
AirAsia's Bhubaneswar-Bangkok service to be temporarily suspended from Sept 25
'Bhoot Part One: The Haunted Ship' to now release in 2020
'Bhoot Part One: The Haunted Ship' to now release in 2020
Two IAS and Four PCS officers transferred
Two IAS and Four PCS officers transferred
To create awareness about new traffic rules, students to form human chain at India Gate
To create awareness about new traffic rules, students to form human chain at India Gate
Mongolian Pres, PM Modi unveils Lord Buddha statue
Mongolian Pres, PM Modi unveils Lord Buddha statue
Delhi's last elephant Laxmi sent to rehab in Haryana
Delhi's last elephant Laxmi sent to rehab in Haryana
Punjab Government transfers 11 DSP officers
Punjab Government transfers 11 DSP officers
Job fair proves boon for unemployed youth as 827 shortlisted for jobs at CT Institute
Job fair proves boon for unemployed youth as 827 shortlisted for jobs at CT Institute
High powered committee constituted by DC holds its maiden meeting
High powered committee constituted by DC holds its maiden meeting