Butterfly wings inspires fraud prevention
6 Jul 2010 by Evoluted New Media
Bank notes and credit cards could be harder to forge thanks to scientists who have discovered a way to mimic bright colours seen on the wings of tropical butterflies.
Bank notes and credit cards could be harder to forge thanks to scientists who have discovered a way to mimic bright colours seen on the wings of tropical butterflies.
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The bright green wings of the butterfly result from mixing of different colours of light that are reflected from different regions of the scales. Credit Mathias Kolle, University of Cambridge |
Rather than relying on pigments, the colours are produced by light bouncing off microscopic structures on the insects’ wings. The wing scales of the Indonesian Peacock or Swallowtail butterfly are composed of intricate, microscopic structures – layers of cuticle and air that produce intense colours and resemble the inside of an egg carton.
“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,” said Mathias Kolle, who –with Professor Ullrich Steiner and Professor Jeremy at the University of Cambridge – made structurally identical copies of the butterfly scales.
These scales produced the same colours as the butterflies’ wings and have helped scientists gain a better understanding of the physics behind the colours
“The artificial structures could be used to encrypt information in optical signatures on banknotes or other valuable items to protect them against forgery,” said Kolle, “We still need to refine our system but in future we could see structures based on butterflies wings shining from a £10 note or even our passports.”
Kolle thinks the butterflies may also be using its colours to encrypt itself – appearing one colour to potential mates and another to predators. Kolle explained that the green patches on the butterflies’ wings appear green to the naked eye, but using the right optical equipment they appear bright blue.
“This could explain why the butterfly has evolved this way of producing colour,” Kolle said, “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.”
