Researchers from the University of New Mexico (UNM) and Los Alamos National Laboratories (LANL) have reported nano-patterning a diffraction grating on human hair with a focused ion to allow the hair to reflect colors in the spectrum to produce a hair color pattern with a flat iron.
In a Journal of Cosmetics, Dermatological Sciences and Applications' paper titled “Nano-Patterning of Diffraction Gratings on Human Hair for Cosmetic Purposes,” UNM research professor of mechanical engineering (and recent retiree from Los Alamos National Labs) Bruce C. Lamartine and UNM professor of mechanical engineering Zayd C. Leseman collaborated on the use of focused ion beam technologies and the way they can be used to pattern different materials.
Their research explores a way to etch diffraction gratings on individual hairs to reflect light in a specific way. The project began in late 2009 when Lamartine, based on work from his previous patents, disclosed a LANL invention for non-chemical directional coloring of hair using milled or impressed nanopatterns. With a subsequent research contract with UNM for focused ion beam (FIB) and related facilities, Leseman and Lamartine explored ion beam etching on single strands of human hair.
Using Lamartine’s ion beam control programs, Leseman and his graduate students Khawar Abbas and Drew Goettler began experimenting with fine etching of the diffraction gratings, which allowed them to create patterns that reflected specific bandwidths of light depending on how far apart the lines were, and how wide and deep they were. By 2011, P&G had funded the project, and the company wanted to see the results of FIB nanopatterning on distinct types of hair. One sample was Asian/black hair, another was European brown hair, while a third sample was blond. The patterning technique proved to be most effective on brown hair, and also produced results on blond and black hair, but the process was cost-prohibitive and the project ended there.
They speculate if someone wanted a permanent change in hair color, they might be able to use something like a flatiron to etch the diffraction gratings into the hair. The color would depend on the portion of the light spectrum that was reflected. Change paddles on the flatiron and change the color, or do special theatrical patterns in the hair, such as changing the diffracted color that the audience sees as an actress walks under a spotlight.The researchers also foresee a conditioner-like polymer coating that could be used with a flatiron to pattern the hair more temporarily until the next wash out.
Other applications for the technology beyond hair patterns could be for credit card readers, ally detection in warfare, prevention of terrorist plane attack, fuel efficient vehicles or to filter bacteria from blood, to name a few. The researchers are looking for entrepreneurs or investors who see the potential in the technology, but they know there is still a lot of work to do.