Researchers have developed artificial ‘chameleon skin’ that changes colour when exposed to light and could be used in applications such as active camouflage and large-scale dynamic displays.
The material, developed by researchers from the University of Cambridge, is made 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 colour thanks to chromatophores: skin cells with contractile fibres 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 Cambridge researchers are built on the same principle, but instead of contractile fibres, their colour-changing abilities rely on light-powered nano-mechanisms, and the ‘cells’ are microscopic drops of water.
When the material is heated above 32C, 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,” said co-author Sean Cormier. “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.”
Learn more: Colour-changing artificial ‘chameleon skin’ powered by nanomachines
The Latest on: Chameleon skin
[google_news title=”” keyword=”chameleon skin” num_posts=”10″ blurb_length=”0″ show_thumb=”left”]
via Google News
The Latest on: Chameleon skin
- Doja Cat Flaunts Strength and Warns Jimmy Fallon’s Audience Not to Stare as She Jokes on The Tonight Showon May 2, 2024 at 5:08 am
T he spotlight was all on Doja Cat when she made an attention-grabbing appearance on The Tonight Show with Jimmy Fallon. The performer had the audience and viewers erupting in excitement as she ...
- Doja Cat fans hastily zoom in after her stern warning to Jimmy Fallon audience as star says she’s ‘beefy and strong’on May 2, 2024 at 2:35 am
DOJA Cat left fans in a frenzy after she showed off her muscles before making a wild demand. The rap music icon spoke to Jimmy Fallon, 49, on his show on Wednesday, and showed off her unique sense ...
- This iconic, universally flattering Clinique lipstick sells out fast — grab it while it's a rare 20% offon April 26, 2024 at 2:55 pm
When it comes to texture, Almost Lipstick is exactly that — an "almost" lipstick. The emollient-rich formula feels more like a nourishing lip balm. It's moist, glossy without being too glossy, and ...
- Chameleon Politics, There Are No Eternal Enemieson April 25, 2024 at 8:09 pm
Furthermore, in the world of politics there is always a saying that there are no eternal enemies, because what is eternal is interest. Based on this adage, moving someone in and out of another ...
- Subversive, self-referential ‘Strange Loop’ gets its Boston premiereon April 25, 2024 at 8:43 am
Other influences for “A Strange Loop” include Kirsten Childs’s 2000 coming-of-age musical “The Bubbly Black Girl Sheds Her Chameleon Skin,” Stew and Heidi Rodewald’s Tony Award-winning bio-musical ...
- BioDome, the Reptile Emporium welcomes its first immense Parson’s chameleonon April 25, 2024 at 8:29 am
BioDome reptile emporium in Libertyville has announced the arrival of the first immense Parson’s chameleon (Calumma parsonii) to its exotic pet collection. This remarkable chameleon, known for its ...
- What exactly is insular dwarfism?on April 23, 2024 at 5:00 pm
In other words what is the process by which, for example, a chameleon the size of your hand ends up being ... You may also like: Anti-acne diet: foods you should eat and avoid to reduce skin problems ...
- Zendaya Transforms From a Spring Bouquet to a Corporate Boss in 2 Very Different Lookson April 23, 2024 at 6:56 am
During an appearance on "Good Morning America” in New York City, Zendaya wore a floral tea dress and a green skirt suit. See the totally different looks.
- What it’s really like to live with a stoma bagon April 23, 2024 at 5:58 am
After 19 operations over a 20-year period, Joanna Prance realised a stoma bag was the solution she had to face up to ...
- Kenita R. Miller, Julia Murney and More Will Take Part in WATCHER IN THE WOODS Readingon April 22, 2024 at 4:47 pm
Producers announced an industry reading of the new musical in development WATCHER IN THE WOODS. Check out all of the details on who will star and who leads the creative team here.
via Bing News