Colour-changing artificial ‘chameleon skin’ powered by nanomachines

Phys.org  August 21, 2019 Researchers in the UK have demonstrated that gold nanoparticles coated with a poly(N‐isopropylacrylamide) (pNIPAM) shell undergo reversible dis/assembly below and above the critical temperature of 32 °C. Loading these particles into microdroplets at high density creates light‐driven artificial chromatophores. Triggering the nanoparticle assembly gives dramatic color changes from nanoparticle localization at the base of the droplets, resembling zebrafish melanophores. These reversible chromatophore states can be switched by both bulk and optical heating. The material could be used in applications such as active camouflage and large-scale dynamic displays…read more. TECHNICAL ARTICLE

Two teams build invisibility cloaks for water applications

Phys.org  August 14, 2019 Two teams of researchers (China, USA – Duke University, South Korea) created passive cloaks using different techniques. Both of them have possible real-world applications. One team created cloak by enclosing an object within a ring of 523 specially designed small pillars—the arrangement of the pillars deflected incoming fluid flow, resulting in zero drag on the object that was hidden. This method could possibly be used to reduce drag on ships or other watercraft. The second approach, based on waveguide cloaks, consisted of installing long, thin iron platforms on the bottom of a tank in its corners. […]

Biological invisibility cloak: Elucidating cuttlefish camouflage

Science Daily  October 18, 2018 Among all animals, cuttlefish, squid and octopuses control their appearance by the direct action of neurons onto expandable pixels, numbered in millions, located in their skin. Researchers in Germany peered into the brain of the cuttlefish and its camouflage control system. They derived minimal rules that may explain skin morphogenesis. They found that chromatophores (specialized skin cells) systematically change colors over time. The study opens a large range of new questions and opportunities in field of cognitive computational neuroscience; help define the precise link between brain activity and behavior and help identify the cellular rules […]