21ST CENTURY NATURE PRINTING: SCIENTISTS STUDY BUTTERFLIES

Brightly coloured patterns on the insects can now be reproduced on banknotes and passports to minimise the risk posed by fraudsters.

Mimicking these iridescent patterns has long eluded scientists as they are produced by light bouncing off microscopic structures in the insects' wings.

But after studying the Indonesian Peacock Swallowtail butterfly, experts at the University of Cambridge have made realistic imitation copies of the butterfly's wings.

It is due to their shape and the alternate layers of air and cuticle within the wings that they produce such depth and intensity of colour.

But scientists found a way to produce structurally identical replicas of butterfly scales.

The copies are created in the lab from a combination of nanofabrication procedures including self-assembly and atomic layer deposition.

Mathias Kolle, who led the research, said: “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.

“These artificial structures could be used to encrypt information in optical signatures on banknotes or other valuable items to protect them against forgery.

To read the complete article, see: Scientists use butterflies in fight against banknote forgery (www.telegraph.co.uk/science/science-news/
7786619/Scientists-use-butterflies-in-fight-against-banknote-forgery.html)

Wayne Homren, Editor

	NBS (coinbooks.org) Web