Scientists at the University of Glasgow have developed an innovative high-resolution printing technology that makes it possible to print two different full-colour images in the same space. The process uses uniquely structured nanomaterials to render colours instead of relying on dyes and pigments, as in traditional printing.
Rather than using dots of pigment to build up an image, this new technique creates microscopic cross-shaped indents (less than one thousandth of a millimetre) in a sheet of ultra-fine aluminium, which then reads as an image when it comes into contact with white light. Which image you see depends on where the light is coming from and how it interacts with the crosses, so essentially, any image can be created by changing the pattern. The nanomaterials allow for much higher-resolution prints, which do not fade over time.
There is a lot of excitement around the potential future applications of this breakthrough – particularly in anti-counterfeiting measures and long-term data storage. The team of scientists have calculated that one A4 sheet of aluminium film could hold a massive 900GB of data. On a more creative level, it could be used to create a new generation of colour filters for digital photography.
For more revolutionary colouring techniques, see Structural Colour: Bird Feathers Inspire Artificial Pigments, Stretchy Structural Colour and Phase-Changing Colour.