The ability to change colors evolved independently several times in the natural world. It can be seen in butterflies, octopus, tetras and-most notably-chameleons. After decades of research, scientists have gained some insight into the mechanics of chameleon color shifts; and recently developed a new “smart skin” that changes color in response to sunlight. This new development could eventually be used for a broad scope of things: such as camouflage or sensors for different kinds of stimuli.
Pictured above: panther chameleons were the primary inspiration for these studies, as they are known to have some of the brightest and most drastic color changes.
Welding, Alan. ambilobe.jpg. 2015. Pics4Learning. 14 Oct 2019
This National Geographic article explains the general process of developing the new smart skin. The scientists associated with this project based their product’s mechanics off of the results from a 2015 Nature Communications publication. In the paper, researchers basically found that chameleon skin contains both dermal cells and guanine crystals. These crystals are different from pigments, which only reflect one hue, and can reflect or scatter light based on size and arrangement. When chameleons want to change colors, they flex or compress these crystals; causing different wavelengths of light to be reflected. And their skin cells expand or shrink to fill in any gaps.
With this knowledge at hand, a team of scientists developed a skin-like material that consisted of a dual-layer hydrogel. One layer contained photonic crystals, while the other contained a colorless polymer. They then exposed the new, artificial skin to direct sunlight. In one experiment, a leaf-shaped skin changed from yellow to green in five minutes. Similar results were seen with a fish-shaped skin. These changes were even faster when a laser was used. However both methods were unique to this field, as most color-changes in labs had previously been stimulated using electric currents.
The technology from this lab can elicit colors without altering the volume of a polymer, an obstacle many engineers have faced in the past. This smart skin could eventually be used for camouflage purposes, or even chemical and environmental sensors. In order to accomplish any of this, though, more research still needs to be done. The material has not yet been produced at a size large enough for clothing or panels. And it currently does not change colors in response to its surroundings. Though, to be fair, neither do chameleons. They change color to reflect mood rather than blend into their surroundings. However, this still remains a big step that can only be improved upon in the future.
Posted by Meagan Gustafson (5)
The material presented in this post is extremely intriguing! I have always wondered about the mechanics behind color change. Previously, I had heard that creatures with such abilities to camouflage did so by flexing dermal tissue but I was never sure about how this would look on the microscopic level. Your last comment made me interested in chameleons and not just their abilities; why would chameleons have their ability to camouflage if not for blending with their environment? I wonder about why chameleons would have a camouflaging ability evolutionarily if it does not promote their survival. As you mention, the chameleon's camouflaging ability is used in revealing mood. How does this mechanism "help" a chameleon in its environment? Does it help the chameleon in finding mates and reproducing?
ReplyDelete-David Frykenberg
I always thought the purpose of chameleon color changes was to blend into the environment as well. It was only when I did research before adopting one that I learned it is more mood-driven than anything. Some animals possess traits that seem counter-productive to survival sometimes; like in cases of runaway sexual selection. Researchers hypothesize that the purpose of changing colors for mood serves as a communication tool with other chameleons. This would make sense, and can be seen in cases when two adult males will exhibit bright colors in an attempt to defend territory.
DeletePosted by Meagan Gustafson
I found this post super interesting. I never thought of the idea of studying how different species use color changing techniques to replicate those same types of techniques to develop clothing. This development could be useful for many things including soldiers out in the deserts or even scientists blending in to study species in their natural habitats. I hope that there is continued research on this topic so that a camouflage cloak/clothing could be developed on a larger scale. I think that this would be a huge benefit for many different types of careers. I also like how you mentioned that chameleons change color based on emotion rather than surrounding. This was interesting to me because anytime I've seen a chameleon, they're always matching their surrounding so I never knew it was emotion based.
ReplyDelete-Sophie DeRepentigny
I like your point about scientists using the synthetic skin to study species in natural habitats. I had only thought of its camouflage capabilities in terms of the military. If the technology advances to a point where it can be produced on a mass-scale, it could also be used for hunting by the general public. Also, most chameleons do match the colors of their environment; but not because they are consciously trying to. I think this may be due to natural selection. Chameleons that display colors similar to their environment when they are feeling neutral/indifferent may have a higher fitness. The bright colors we often think of are usually displayed in times of stress (territory defense, meeting rival males, etc.).
DeletePosted by Meagan Gustafson
Wow this article was really interesting and just showed how technology is advancing every day. I never thought that this would be something that would be invented. Animals do such amazing things and it's crazy that we are finding ways to copy them. I also found it really interesting that chameleons flex when they want to change color. I wonder how this is going to work when it is created for human use. Will they have some type of control panel or will it activate from touch/flexing? It is a topic that can bring many questions. This will definitely be a really useful invention for the military, making missions a lot easier that require soldiers to be hidden. It will be really cool to see this product once it is finished. Awesome post.
ReplyDelete-Matt Cayer