A graphene coating that can change color when it cracks isn't just cool materials science -- it could actually save lives.
That’s thanks to researchers at Germany’s Leibniz Institute of Polymer Research, who have developed a smart graphene coating which shows breaks and fractures by changing color.
“Extensive research efforts all over the world focus on single-layer graphene, and graphene enables a wide array of functional coatings and paints for many possible applications,” Shang-Lin Gao, a scientist in Leibniz Institute’s Department of Composite Materials, told Digital Trends. “However, our work only considers multilayer graphene nano-platelets with a widely distributed size and thickness. Variable structural coloration is achieved for the first time by overlapping these graphene nanoplatelets. The color changing is sensitive to nanoscale mechanical deformation. It provides the possibility for the early warning of microcracks prior to a material’s failure.”
Inspired by the way that fish scales reflect light, the scientists involved in the project designed a coating which amplifies particular wavelengths of light, but dulls others. The graphene flakes are then placed at certain angles so that, if compromised in some way, they’ll bounce back red, yellow, and green light, while noncompromised areas do not. Cleverly, the color of light can change according to the severity of an area’s stress, so structures could conceivably be color-coded to show how severe a particular area of damage is.
“The potential industrial applications for this graphene coating could be not only structural materials [on] vehicles, ships [etc.] for checking nanoscale deformation, but also smart house, textiles for fashion, [and more,]” Gao continued.
At present, the work is still in its early stages. Gao noted that there is still much to be done in terms of research and investment in order to solve challenges related to scaling-up manufacturing, parameter control, and more in order to make this a reality.
However, if these are solved effectively, color-changing graphene coatings could potentially be an invaluable tool in the arsenal of designers, structural engineers, and more.