Butterfly wings as model for counterfeiting
A butterfly wing produces strikingpatterns using the physical structure of the wing's surface without resorting to gaudy pigments. Coloureffects can be produced using light scattering, diffraction, interference, andiridescence but with the exception of security holograms and optically variable ink onbanknotes, these effects have not yet been used widely.
The Cambridge team will explore systematicallycolour effects achieved using a combination of optical phenomena due tonanoscale physical patterns on surfaces. These will include multilayers,diffraction gratings, fluorescent nanoparticles, tilted layered structures andmicro-prisms and lenses. They suggest that they can develop a strategy for themanufacture of a label that has a strong and brilliant colour, that changesdepending on the angle you look at it or how it is lit and does not requireclose examination. Such a label produced using any of these nanoscopic physicalsystems would be virtually impossible to replicate or copy.
Source: epsrc.ac.ukAdded: 20 October 2006