(NanoRealm) - Banknotes could become as beautiful as butterfly wings one day using technology borrowed from nature.


British scientists have found a way to mimic the iridescent colours of tropical butterflies, created by light bouncing off microscopic wing structures.

The research could be used to make banknotes and credit cards that are visually striking and harder to forge.

“These artificial structures could be used to encrypt information in optical signatures on banknotes to protect them against forgery,” said Mathias Kolle, a PhD student at the University of Cambridge.

“In future we could see structures based on butterflies’ wings shining from a £10 note or even our passports.”

The Cambridge team studied the Indonesian peacock, or swallowtail, butterfly — Papilio blumei — whose vivid green-and-blue wings have an intricate surface pattern.

They made identical copies of the structures using nanotechnology.

Recreating the colours of beetles, butterflies and moths has previously proved elusive because of the technical challenge of precisely shaping materials on such a small scale.


“We have unlocked one of nature’s secrets and combined this knowledge with state-of-the-art nanofabrication to mimic the intricate optical designs found in nature,” Mr Kolle said.

“Although nature is better at self-assembly than we are, we have the advantage that we can use a wider variety of artificial, custom-made materials to optimise our optical structures.”

The research is published in the journal Nature Nanotechnology.

The Indonesian peacock may use the security potential of its wing structure to encrypt itself, the scientists believe.

“The shiny green patches on this tropical butterfly’s wing scales are a stunning example of nature’s ingenuity in optical design,” Mr Kolle said.

“Seen with the right optical equipment these patches appear bright blue but with the naked eye they appear green.

“This could explain why the butterfly has evolved this way of producing colour. If its eyes see fellow butterflies as bright blue, while predators only see green patches in a green tropical environment, then it can hide from predators at the same time as remaining visible to members of its own species.”

TimesOnline UK: (http://www.timesonline.co.uk/tol/news/uk/article7140807.ece)