There are so many man-made structures around the world that can fail without any prior notice; bridges and airplanes just being 2 examples of it. It is previously also shown that such constructions do provide indication but are too small to be noticed. For instance, parts of the plane can develop small cracks, which can result in failure in situations of sudden stress.
Several substances are colored by chemical pigments that take up light at a specific wavelength and return the residual light that is visualized as color by us. On the other hand, substances are provided color by occasionally arranged microscopic surface structures. This result in a hindrance between reflected light waves, intensifying them at certain visible frequencies. This approach is utilized in few of most vibrant substances in nature, from peacock feathers to fish scales, cephalopod skins, and butterfly wings.
Taking inspiration from these models, a research group at the Leibniz Institute of Polymer Research, led by Shanglin Gao, has designed a structurally colored coating consisting of graphene flakes (nm sized), which alter the color based on the colored surface’s deformation. With the motivation from natural radiance in fish skin, the graphene coating can offer an easy method to notify about the out of sight damage in bridges, buildings, and other structures.
The researchers developed a coating that appears to be red; however, when it deforms, the color changes to yellow, whereas when it is cracked at µm scale, the color changes to green. This color-altering capability is obtained from a vigilant arrangement of the graphene flakes in lucid, parallel layers, coating a glass fiber. In stressful circumstances, the layers constrict and flatten, thus altering the interference and reflected light’s color. In reality, by lapping over graphene nanoplatelets with disordered and ordered characteristics using a specific deposition method, distinctive fish scale-like arrangements are obtained. Changeable structural coloration is seen via the mechanical regulation of fine parallel multilayers.
However, before its application in the real world, more testing will be required to validate the behavior and properties of the coating. Also, it is necessary to verify how much efficient the material is at disclosing the cracks and deformations.
This is a unique way of detecting damages in structures and hopes this can prevent major accidents caused due to unnoticed damages. What do you think?