
Chameleons Are Masters of Nanotechnology
Season 5 Episode 18 | 3m 48sVideo has Closed Captions
What do chameleons have to do with nanotechnology?
What do chameleons have to do with nanotechnology? These color-changing lizards are some of nature’s wackiest animals, all because they’re masters of pigment and light. This week on Reactions, learn all about the chemistry of chameleon color.
Problems playing video? | Closed Captioning Feedback
Problems playing video? | Closed Captioning Feedback

Chameleons Are Masters of Nanotechnology
Season 5 Episode 18 | 3m 48sVideo has Closed Captions
What do chameleons have to do with nanotechnology? These color-changing lizards are some of nature’s wackiest animals, all because they’re masters of pigment and light. This week on Reactions, learn all about the chemistry of chameleon color.
Problems playing video? | Closed Captioning Feedback
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Learn Moreabout PBS online sponsorshipChameleons are a top-tier freaky pet that you just can't help but be mesmerized by and their active color changing abilities are a picture perfect example of chemistry going hand in hand with evolution.
Believe it or not, these oddball reptiles are actually working with a different chemical toolbox than cephalopods and their other color-changing counterparts.
Today we're looking how they work their magic, and how it's inspired scientists to invent up-and-coming technologies!
One thing that really stands out about chameleons is that they always have this suspiciously chilled out look on their faces, but that's not all when it comes to bizarre features.
Their feet are zygodactylous, with three toes facing forward and two going the opposite direction.
They also have monocular vision, so their eyes can move about and focus independently from each other!
If you've ever seen a chameleon eat, then you also know about their amazing projectile tongues!
But the cream of the crop of their freaky features is going to have to be their psychedelic skin.
Chameleons have the ability to actively change both their color and brightness.
While it's often thought to be used for just camouflage, scientists believe that there are two other fundamental uses, the first being intra-specific communication, and the second being a means for thermoregulation.
Because chameleons are cold blooded, they need sunlight to heat themselves up to get their metabolism running.
By controlling how bright or dark they are, they can better regulate how much heat they take on.
And while their color changing may not seem to stand out from cephalopods and others, they do have a chemical mechanism that sets them apart from the crowd.
Cephalopods and chameleons have color-changing cells called chromatophores that carry pigments inside of them that can be displayed at will; however, there is a big difference between the two.
The chameleon's version comes equipped with an advanced layer of nano-science.
This colorful little guy is known as a Panther Chameleon, and its skin can exhibit a range of these specific colors Here's where it gets interesting: only /these/ specific colors can be displayed by the typical pigments release by chromatophores.
So where do they get those whites, blues, and greens?
From unique cells called iridophores.
Iridophores aren't filled with pigments but instead with tiny little structures of nano-crystals that can produce iridescent blue light at their resting state.
The chameleon can excite these crystals, rearranging them into a different structure that changes the wavelengths of light that they absorb and reflect.
This turns them from blue to white.
We're not sure exactly how chameleons control their iridophores, but we suspect that they're working with either neural or hormonal controls.
And while some cephalopods are packing iridophores too, chameleons are the ones that have truly mastered them.
Inside the panther chameleon's skin are several layers of different colored chromatophores.
The top layer contains a mix of yellow xanthophores and red/orange erythrophores.
The bottom layer has brown, melanin-bearing melanophores.
Mixed into the top layer of red and yellow chromatophores are your iridescent light generating iridophores, and in-between these two layers you find reflective iridophores.
The chameleon changes its skin color by adjusting the pigments released by their chromatophores, and then takes things one step further by using those iridophores to change the way the way we perceive the chromatophores pigments.
For example, the Panther Chameleon can produce a green color because those resting nanocrystals reflect blue light, so pair that with the yellow pigment, and your eyes perceive green.
Then when excited, the blue becomes white which will make the yellow xanthophores stand out more prominently.
This use of nanocrystals is so ingenious that it even inspired scientists in China to come up with their own active camouflage nanotechnology!
Instead of of iridophores, these researchers created tiny gold nanoparticle domes that they housed in cells filled with a silver ion loaded gel.
By sending different charges through the gel, silver ions will tack onto, or break off of the gold nano-domes which changes the wavelengths of light they absorb and reflect.
The team attached this system to cameras and can currently change the active color of the cells to red, green, and blue.
So what do you think?
If this technology keeps advancing, will we ever see active camouflage as advanced as the Predator's?
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