The new material changes color due to stretching and pressure. The researchers studied the structure of chameleon skin and replicated the same mechanisms in artificial structures.
The researchers took inspiration from the device of chameleons and developed technology that can change the color of the material. Scientists have presented a flexible film that changes depending on stretch, pressure, or humidity. They report their findings to ACS Applied Materials & Interfaces.
Experts have mimicked the crystalline nanostructures of chameleon skin in a variety of color-changing materials, but these tend to be difficult to manufacture. This time, they simulated the technology in cellulose nanocrystals, a renewable material that can self-organize into a film with iridescent structural colors.
To increase the flexibility of cellulose nanocrystals, the researchers added PEGDA polymer and used ultraviolet light to combine it with rod nanocrystals, creating films with bright rainbow colors ranging from blue to red, depending on the amount of PEGDA. The films have become strong and flexible, stretching up to 39% of their original length. During stretching, the color of one film gradually changed from red to green, and then changed back when relaxed.
According to the researchers, they showed for the first time-reversible structural color changes caused by stretching and relaxation, which are visible to the naked eye. The film also changed color with changes in pressure and humidity. According to the researchers, the new “smart material” could find application in encryption and anti-counterfeiting.