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Nanotech and Medicine

Crime-Fighting Bugs

Butterflies are famous for their vibrant colours and eye-catching wing patterns, but researchers are finding ways that we can put these impressive patterns to use for fighting crime.

Whether it’s for camouflage or attracting a mate, warning off a predator or identifying family, the diversity of insect colouration is practically endless.


By studying these gorgeous critters we now know that all these colours and patterns are created not with pigments (which is what most other animals use for colouration), but with the microscopic structures arranged in layers which causes light to bounce around and be reflected in all kinds of interesting ways to produce intense colours!

Close up photo of Blue Morpho butterfly wing
Blue Morpho Butterfly Wing

Butterfly wings are particularly good at this and can even appear as different colours to different animals. While other butterflies might see a bright blue pair of wings, predators spotting the butterfly might only see a dull green instead because of how the light is reflected and the kinds of eyes that are looking at them.

Engineers have found ways that this complex colouring can be used when designing bank notes. If you have a look at a £5 note you’ll notice all kinds of interesting patterns and colours that are designed to make it very difficult for criminals to print fake money. By copying the structures like those found on a butterfly’s wing into our bank note designs, insects are helping us to stop fraud at the microscopic level by making it nearly impossible to copy without special machines and experts. 

Bank Notes from Around the World
Bank Notes from Around the World