![]() They are also sensitive to chemicals that are washing around in the blood stream of the chameleon. Now, how does the chameleon change colour? Well those chromatophores are wired up to the nervous system. And underneath that is another layer of cells called melanophores which have a brown pigment – melanin – in them. Beneath that, another layer of cells called iridiphores have a blue coloured pigment called guanine, which is actually also used in making DNA. Beneath that are pigment cells which are called erythrophores which have a red colour in them. These are xanthophores, containing particular specialised pigments that have a yellow colour. On the outer surface of the chameleon, the skin is transparent and just below that is the first layer of these cells, and they contain various pigments. If you look at the skin of a chameleon, you find that they have several layers of specialised cells called chromatophores and these are cells that can change colour. The way that chameleons actually do this is on a molecular level – you could say that they’re molecular masterminds, really. Some chameleons, for example the stump-tailed chameleon, rock back and forward to look like leaves being blown by the wind. The high arched back gives their body a leaf-like shape and their slow movements make it difficult for predators and prey to detect them. In addition to this miraculous ability their body shape also helps with camouflage as well as the way they move. They can thus blend into their surroundings by altering the colour of their skin to match the background.Ĭhameleons will also use their ability to switch colour during social displays when they alter their colouration and pattern dramatically from the background. They do this by expanding or contracting cells in their skin that contain different pigments. This feat of magic is common to most chameleons. The new bio-based smart skin could find applications in strain sensing, encryption and anti-counterfeiting measures, the researchers say.Chameleons camouflage themselves in a variety of different ways but most famously by changing the colour and pattern of their skin. The film also changed color with pressure and humidity, allowing the team to show or hide writing made by an inkless pen. According to the researchers, this is the first time that stretching- and relaxing-induced, reversible structural color changes that are brilliant and visible to the naked eye have been realized for cellulose nanocrystal materials. During stretching, the color of one film gradually changed from red to green, and then changed back when relaxed. ![]() The films were both strong and flexible, stretching up to 39% of their original length before breaking. To increase the flexibility of cellulose nanocrystals, the researchers added a polymer called PEGDA and used UV light to crosslink it to the rod-shaped nanocrystals, producing films with bright iridescent colors ranging from blue to red, depending on the PEGDA amount. Fei Song, Yu-Zhong Wang and colleagues wanted to develop a highly flexible film made of cellulose nanocrystals that changes color when stretched. However, the films are typically fragile and, unlike chameleon skin, can't be stretched without breaking. ![]() In contrast, cellulose nanocrystals are a renewable material that can self-assemble into a film with iridescent structural colors. Scientists have mimicked the crystalline nanostructures of chameleon skin in various color-changing materials, but they're typically difficult to produce, or they rely on non-renewable petroleum resources. These structural colors are different from the pigments that give many other creatures their hues. ![]() By tensing or relaxing their skin, chameleons can change the way light reflects from guanine crystals under the surface, producing what's known as structural coloration.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |