SEM image showing that the surface of a wing scale is covered with concavities (Image: Mathias Kolle, University of Cambridge)
SEM image of concavities is covered by a conformal multilayer stack of 11 alternating layers of titania and alumina (Image: Mathias Kolle, University of Cambridge)
The bright green wings of the P. blumei butterfly result from the mixing of the different colors of light that are reflected from different regions of the scales (Image: Mathias Kolle, University of Cambridge)
Counterfeiting is a crime as old as money itself. It causes a reduction in the value of real money and can add to company losses, as they are not reimbursed for counterfeits. In 1996 Australia became the first country to have a full series of circulating polymer banknotes, which are difficult to counterfeit because they cannot be successfully reproduced by photocopying or scanning. Now scientists have discovered a way of mimicking the stunningly bright and beautiful colors found on the wings of tropical butterflies, that could help make banknotes and credit cards even harder to forge.
Other Images from this Gallery