As we all know, chameleons have the ability to change their body surface’s color to camouflage themselves, communicate with each other  and regulate their temperatures. 

The real science behind this color-changing property in chameleons was the tensing and relaxing of their bodies. When they did so, the guanine crystals (transparent platelets) present inside their body surface reflected the light in a way that produced structural colors (colors formed by nanostructures which reflect light in specific wavelengths).

In the past, there have been many attempts to replicate this property but everytime, there used to be a limitation or fault in the outcomes. The most similar structures to those of chameleons were cellulose nanocrystals. But, a concerning limitation was that it wasn’t as flexible and strong to be stretched and relaxed repeatedly.

But now, scientists have made these cellulose nanocrystals stronger and flexible by using UV light and adding a polymer called PEGDA. This has led to the creation of a film which can change its colors according to the pressure and humidity. According to researchers, this new bio-based smart skin can find applications in strain sensing, encryption, and anti-counterfeiting measures.

FUN FACT: By using this, you can write with an inkless pen.