Creating Colour With Nano-patterns

Changing hair colour through pattern

Engineers at the University of New Mexico have developed a means of changing hair colour through the use of pattern alone. This technology is based upon the phenomenon of structural colour, whereby the spectrum of light absorbed or reflected by an object – and therefore its perceived colour – is determined by the pattern of microscopic ridges on its surface.
A focused ion beam can etch spirals and hyperbola into individual strands of hair; the depth and width of the lines and the distance between them determines the bandwidth of light reflected. These nano-patterns can be manipulated to create desired colours without the use of dye, thus demonstrating the effect an almost-invisible pattern can have on our everyday visual reality.
Photo: Nano patterns etched into hair. University of New Mexico
At the moment, only individual hair strands can be coloured, and the change remains until the hair grows out. However, the team behind the innovation are exploring the possibilities of wash-out colour changes through the use of ion-etchable polymer coatings, as well as other potential applications. Non-toxic and without any nasty chemicals, structural colours could be coming to a salon sometime soon.