Chameleon-like: Scientists create color-changing artificial 'skin'
A chameleon robot covered with artificial skin that can change its color based on surroundings is seen in Seoul, South Korea, Sept. 7, 2021. (Reuters Photo)


Chameleons are a unique species with the ability to match their surroundings, the mechanics of which have always intrigued humans. Well, South Korean researchers now believe they have cracked the code, saying that they have developed an artificial skinlike material, inspired by natural biology, that can quickly adjust its hues much like a chameleon.

The team, led by Ko Seung-hwan, a mechanical engineering professor at Seoul National University, created the "skin" with a special ink that changes color based on temperature and is controlled by tiny, flexible heaters.

"If you wear woodland camouflage uniforms in the desert, you can be easily exposed," Ko told Reuters. "Changing colors and patterns actively in accordance with surroundings is key to the camouflage technology that we created."

Chameleon robot covered with artificial skin changing its skin color based on surroundings, from green with red, and blue with green, is seen in Seoul, South Korea. (Ko Seung-hwan via Reuters)

Ko and the team demonstrated the technology – thermochromic liquid crystal (TLC) ink and vertically stacked multilayered silver nanowire heaters – using a robot with color-detecting sensors.

Whatever colors the sensors "saw" around it, the skin tried to mimic.

In a video, the robot crawled over red, blue and green floors, instantly changing color to match the background.

"The color information detected by sensors is transferred to a microprocessor and then to silver nanowire heaters. Once the heaters reach a certain temperature, the thermochromic liquid crystal layer changes its color," Ko said.

Ko Seung-hwan, a mechanical engineering professor at Seoul National University, looks at a chameleon robot covered with artificial skin, in Seoul, South Korea, Sept. 7, 2021. (Reuters Photo)

The total thickness of the flexible, multilayered artificial skin is less than a hundred micrometers – thinner than a human hair. By adding additional silver nanowire layers in simple shapes such as dots, lines or squares, the skin can create complex patterns.

"The flexible skin can be developed as a wearable device and used for fashion, military camouflage uniforms, the exterior of cars and buildings for aesthetic purposes, and for future display technology," Ko said.

The research was published in the journal Nature Communications in August.