London - Dyeing your hair can be time consuming and expensive, not to mention damaging.
So most women would welcome a new invention that could change their hair colour at home at the touch of a button.
Scientists have taken the first step to making this possible and believe that a device similar in appearance to hair straighteners or flat irons, could be used to colour and even press a pattern into your hair in the future.
Engineers at the University of New Mexico and Los Alamos National Laboratories are researching the use of focused ion beam technologies and the way they can be used to pattern different materials, including hair.
Professors of Mechanical Engineering, Bruce Lamartine and Zayd Leseman, are exploring a way to etch “diffraction gratings” on individual hairs to reflect light in a specific way.
The project began five years ago when Professor Lamartine had the idea for a way of colouring hair without chemicals using nanopatterns.
Using a focused ion beam (FIB) – which are already used in the manufacture of electronics – the engineers created patterns on single strands of human hair that reflected specific bandwidths of light depending on how far apart the lines were and how wide and deep they were.
They used patterns called Archimedean spirals and hyperbola patterns to achieve reflect light in a certain way so that it appeared to change colour.
They tested their idea on black, brown and blonde hair, finding that the technique was most effective on brown hair.
While using a million-dollar machine to “colour” individual strands of hair is not practical for people covering up greys at home, the engineers think that with more research, a hair straightener-like device could be created to permanently change the colour of someone’s hair.
It would work by etching the diffraction gratings into the hair and the colour would depend on the portion of the light spectrum that was reflected, according to the research, which was published in the Journal of Cosmetics, Dermatological Sciences and Applications.
Users of the futuristic device could change “paddles” on the device depending on what colour they wanted their hair to be and could even create patterns in it by changing the diffracted colour.
Professor Leseman said: “That’s one way to do it, to make the pattern directly onto your hair...and that would be more of a permanent change until it grows out.”
“The other idea...is to actually develop some kind of conditioner - some kind of polymer coating for your hair.
“Then when you do the patterning with your flat iron that’s specially developed for this polymer coating - maybe low heat - then you could actually pattern the conditioner or the polymer on your hair.
“And then it would easily wash out if you wanted it to go away, so that’s not as permanent and as scary.”
As well as allowing people to have rainbow-hued hair without the damaging effects of using bleach, the technology could have more serious applications.
It could be used as a security measure on credit card readers. It could also be used to identify friend from foe on the battlefield.
“We talked about the possibility of an optical band pass and this would lead to identifying a friendly soldier if you can wear a pattern like this, possibly on an armour jacket,” Professor Lamartine said.
“The identification could change like the old style military code books. You could issue a new roll of tape with a different pattern on it once a month and you know that there’s a certain colour of laser which will return from that. If it is somebody else’s pattern, then you know you don’t have a friendly.”
The researchers say the technique of etching diffraction gratings on materials could be used to defend against potential terror attacks on civilian airplanes.
Print specific diffraction gratings on a roll of polymer, attach it to the underside of a jetliner and the jet becomes invisible to the laser sights on missiles, they explained. The aeroplane would essentially become a ghost plane to terrorists.
It could also be used to build more efficient injection engines in order to boost fuel efficiency in cars or even as a mechanism to filter viruses or bacteria from blood or other body fluids, they said. - Daily Mail