Camouflage: Octopus-inspired material changes colour to blend in


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Wrinkles in this material can help camouflage an object

Xuesong Jiang

Many camouflage materials are limited by the need for power or external sensors as they effectively record video of what is behind an object to be hidden and display it on the front. Instead, a new material inspired by octopuses and squid shines an infrared torch on an object to match its surroundings.

Xuesong Jiang at Shanghai Jiao Tong University in China and his colleagues have created the material from two layers, each of which has a different thermal expansion rate. One layer is infused with pigments of mixed colours and the other is made to be the same colour as the background.

When the material is cool, the layers have different tensions, which causes tiny wrinkles and creases to form on the surface. Light shone onto the surface warms up the layers, causing them to expand at different rates and making the two materials smooth again.

Creating and eradicating these wrinkles allows the colour of any reflected light to be controlled. In the wrinkled state, a mixed spectrum of bright colour is reflected, but when the material smoothes out, the reflected colour matches the background, and whatever is clad in the material becomes camouflaged.

Because the system doesn’t use sensors or power, researchers believe it could create inexpensive adaptive camouflage uniforms. The US Army has previously made a call for proposals for wearable camouflage with chameleon-like abilities.

Journal reference: PNAS, DOI: 10.1073/pnas.2114345118

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