Researchers are developing a technology that could one day make paint and color packaging labels that never fade.
The color is produced by a type of nanostructure called a “plasmonic pixel.” These pixels are made of aluminum nanoantennas, and when the free electrons in the metal collectively vibrate at specific frequencies, they produce a specific color.
In a new paper published in Nano Letters, Timothy D. James, Paul Mulvaney, and Ann Roberts at The University of Melbourne have demonstrated a new plasmonic pixel design that addresses several of the critical problems facing plasmonic color images, including a limited number of colors, small image size, and difficulty in creating accurate colors without using complex color-mapping algorithms.
The new plasmonic pixel design uses an algorithm that can produce nearly 2000 different colors and shades and achieve a resolution that exceeds the resolution limit of the human eye. To demonstrate, the researchers fabricated a 1.5-cm-long image (which is relatively large compared to previous plasmonic images), and showed that colors could be accurately reproduced using a straightforward color-mapping algorithm.
Although other areas of plasmonics research may have potential applications as displays for phones and TVs, this plasmonic pixel produces a static image, where the color and structure are set at the time of fabrication and can’t be altered.
“The potential applications for the plasmonic pixel (and other color-producing nanostructures in this research space) would be as an industrial paint on cars, buildings, advertising billboards, etc., as the plasmonic pixels will never fade,” James told Phys.org. “With the ability to print at resolutions greater than conventional pigment-based processes, the plasmonic pixels may also have applications in security-based devices for use on high-value product packaging, medicines, etc.”
Read more at: phys.org.
