The research, published in the journal Advanced Functional Materials, describes the development of nano-scale plasmonic colour filters that display different colours depending on the orientation of the light which hits it.
This technique allows the ‘printing’ of two entirely different, but exceptionally detailed, full-colour images within the same surface area.
Instead of relying on dyes and pigments, as in traditional printing, structural colour uses specially structured nanomaterials to render colours.
As a result this allows for much higher-resolution prints which do not fade over time.
A typical printed image in a magazine, for example, might consist of around 300 coloured dots per inch of page, or 300 DPI. A page ‘printed’ with structural colour techniques, however, could reach a resolution of 100,000 DPI or more.
The Glasgow team have added a nanoscale element in the structural colour process.
Dr Alasdair Clark is the lead author of the research paper, writes:
“We’ve discovered that if we make colour pixels from tiny cross-shaped indents on a strip of aluminium film, the colour they display becomes polarisation-dependent, allowing us to encode two colours into a single pixel, and then select which colour is displayed by shining different polarisations of light at the surface.
“By changing the size and shape of the nanoscale indent, we can create a wide range of different colours at very high resolutions.”
According to Dr Clark potential applications for this plasmonic colour technology include long-term data archival due to its ultra-high resolution.
“We’ve worked out that we could store 1.46Gbit per square centimetre, so a single A4 sheet could hold more than 900Gbit of data,” said Dr Clark.