Inspired by butterflies, researcher invents new paint that has no pigments

Inspired by butterflies, Debashis Chanda, a professor at UCF and head of the Nano-optics research group, set out to make a paint that does not use pigments, as stated by the press release.

How does the pigment-less paint work?

Conventional paints carry pigments that rely on the light absorption properties of molecules to determine their colors. The light that is not absorbed is reflected back and seen by the observer and associated with the object's color.

The paint made by Chanda's team relies on light absorption as well as reflection and scattering of the geometric arrangement of its nanostructures to create a full-color palette. Chanda's inspiration for this was nature itself, where flowers, birds, butterflies, as well as underwater creatures exhibit attractive hues, all created by the geometric arrangement of colorless materials.

Chanda's team replicated these geometric arrangements using nanoscale aluminum and aluminum oxide, negating the need for new pigment molecules for different colors. The nanoscale flakes can be mixed with a commercial binder and make paints of different hues.

Since the paints only contain metal and its oxides, it is environment friendly too. "Normal color fades because pigment loses its ability to absorb photons,” Chanda said in a statement. “Here, we’re not limited by that phenomenon. Once we paint something with structural color, it should stay for centuries.”

The paint also reflects the entire infrared light spectrum, absorbing less heat. Compared to commercial paints, the plasmonic paint kept surfaces more relaxed by up to 30 degrees Fahrenheit during tests, the researcher added. This temperature difference could also help reduce air conditioning needs inside a building, reducing power consumption and carbon emissions in the long run.

The paint is also extremely lightweight. The researcher claims that full coloration can be achieved using only 150 nanometers of this paint, making it the lightest paint in the world. While 1,000 pounds of commercial paint would be needed to paint a Boeing 747, only three pounds of plasmonic paint could get the job done.

The research findings were published in the journal Science Advances.

Study Abstract:

All present commercial colors are based on pigments. While such traditional pigment-based colorants offer a commercial platform for large-volume and angle insensitiveness, they are limited by their instability in atmosphere, color fading, and severe environmental toxicity. Commercial exploitation of artificial structural coloration has fallen short due to the lack of design ideas and impractical nanofabrication techniques. Here, we present a self-assembled subwavelength plasmonic cavity that overcomes these challenges while offering a tailorable platform for rendering angle and polarization-independent vivid structural colors. Fabricated through large-scale techniques, we produce stand-alone paints ready to be used on any substrate. The platform offers full coloration with a single layer of pigment, surface density of 0.4 g/m2, making it the lightest paint in the world.