Nanotech researchers develop a new structural color solution

18-Sep-2017 - Last updated on 20-Sep-2017 at 12:10 GMT

A team of scientists from around the world, led by Ming Xiao of The University of Akron, have just published their findings online at Science Advances. The researchers are optimistic that their noniridescent structural color solution can be useful on a commercial scale in industries including cosmetics.

The research team behind the new technology is comprised of scientists working at The University of Akron, Northwestern University, the University of California, Sichuan University (China), Shanghai Jiao Tong University (China), and Ghent University (Belgium).

Their article entitled ‘Bioinspired bright noniridescent photonic melanin supraballs’ was published late last week on the Sciences Advances journal site.

Bugs

Many previous advances in structural color have taken inspiration from the iridescent colors of insects.

An article published by the American Chemical Society earlier this summer celebrated insect-like structural color that can be modified after it's created. Korean researchers “Kim, Lin, and An…documented a ‘method [that] combines the advantages of top–down and bottom–up synthetic approaches in that the structural color can be continuously modified once fabricated,’” as Cosmetics Design reported at the time.

And beauty makers like L’Oréal and HairPrint are working with structural color technology. L’Oréal hopes to leverage the right tech to put structural color to use in color cosmetic product formulations, while HairPrint uses the technology of exoskeletons to return grey hair to its natural color. (Read more here.)

Birds

For the research and findings published this month, however, scientists took their cues from duck and turkey feathers. “Drawing inspiration from nature’s many examples of structural colours, Ming Xiao at the University of Akron and colleagues examined the structures of a duck wing feather and an iridescent turkey wing feather to create an optical model without iridescence,” according to an item about the new color technology from the editorial staff at Cosmos Magazine.

Biochemistry

To oversimplify, the new color tech is a nanoparticle made of melanin and silica. And the thickness of each determines the quality and shade of color.

“We have designed core-shell nanoparticles using high–refractive index (RI) (~1.74) melanin cores and low-RI (~1.45) silica shells,” explains the team in their article abstract. The abstract goes on to say that “the design of these nanoparticles was guided by finite-difference time-domain simulations. These nanoparticles were self-assembled using a one-pot reverse emulsion process, which resulted in bright and noniridescent supraballs.”

The researchers believe this new tech can be replicated at a commercial scale useful in and beyond beauty: “With the combination of only two ingredients, synthetic melanin and silica, we can generate a full spectrum of colors. These supraballs could be directly added to paints, plastics, and coatings and also used as ultraviolet-resistant inks or cosmetics.”

The full-text version of ‘Bioinspired bright noniridescent photonic melanin supraballs’ can be found here.