This Robot changes its color like a chameleon! A team of researchers from South Korea has created a robot chameleon that can mimic its biological counterpart using an artificial camouflage. The research of the new artificial camouflage technology was published in Nature Communications, an open-access journal. 

The chameleon animal’s secret to its color-changing ability comes from a specific layer of cells under the skin called iridophores. Like the animal chameleon, the researchers could re-create several high-resolution skin patterns that allowed the Robot to switch between colors. Swiftly using color sensors and small heaters comprised of silver nanowires as thermochromic materials, the Chameleon Robot can change color when subjected to extreme temperatures. 

The chameleon-inspired walking robot is 1 foot and 3 inches long, 6 inches wide, and weighs 2 pounds. The bottom of the Robot is equipped with color sensors and feedback systems that detect the backdrop color to change its skin color.

There have been experiments into artificial camouflage technology that used microfluidic devices, which utilize small channels to regulate the flow of fluids within it. But, this project is built on an electric approach.

According to professor Seung Hwan Ko, the biggest challenge was making the color change just like the chameleon’s speed.

Seung Hwan Ko is one of the chameleon robot study authors and a thermal engineering professor at the Seoul National University. He said that the team overcame this challenge by employing nanowire heaters that heat up in a short time. The nanowire heaters helped the artificial skin of the chameleon robot warm up quickly, which was sufficient to change color just like a real animal chameleon. 

The first chameleon design prototype was slow. Initially, the team decided on the Robot’s structure whether the Robot would be based on an invertebrate, such as snails or octopuses, or a vertebrate, such as a dog. The initial prototype was decided to imitate the octopus because an invertebrate model would provide for more flexibility. But this prototype was very ambitious, says Seung Hwan Ko. 

After several revisions with varied designs and materials, in the end, the team chose to stick with the chameleon’s basic structure. The research team generated the intricate effect displayed in this video by forming the nanowires into simple patterns made of dots, lines, or scale forms.

In the past, research into artificial camouflage has been mostly focused on military applications. But, Seung Hwan Ko expects their chameleon robot project will have a broader impact, particularly in the domains of transportation, beauty, and fashion. In the future, it could be helpful in the automobile industry where cars change colors to stand out or in the cloth industry with color-changing textiles.

The chameleon study reveals that the chameleon’s skin and the surface are simply a soft, elastic, and flexible display. The technology used in the research is wholly dependent on temperature, because of which it doesn’t perform up to the team’s expectations. Due to which the Robot’s ability to perceive the complete spectrum of color may be compromised.

Although the Robot is somewhat larger than a natural chameleon, researchers hope to reduce its size in future versions. According to the team, a higher-resolution reflection of backdrop textures is also on the agenda, which may be achieved with better signal processing and data-driven research.

The bio-inspired robotics researcher Ramses Martinez, an assistant professor at Purdue University in West Lafayette, Indiana, believes that converting other biologically inspired systems into technological innovations could lead to more applications, including devices that aid locate survivors after an earthquake.

The technology employed in the chameleon-inspired Robot could have several other applications. Not just in one industry, it can be used in multiple industries, for example, spot enemies, create aesthetics, and many more. The study has paved the way for more technological innovations in the robotics industry.