The brilliant colours in a butterfly's wings, for example, are not produced by pigments alone. Instead a diffraction grating - a series of microscopic grooves on the surface of the wing - creates the vivid colours. Michael Gale of CSEM Zurich, Switzerland, is investigating how to produce similar structures on credit cards and bank notes as a security measure. Meanwhile Chris Lawrence of the Defence Evaluation Research Agency and Peter Vukusic from Exeter University have been looking at ways to make pigment-free paint, again inspired by butterfly wings.

The techniques used by flies to detect movement have also inspired physicists. Nicholas Franceschini of the Laboratory for Neurocybernetics in Marseilles has reproduced in electronics the pattern of neurones responsible for vision in flies, and built a robot that is capable of moving about among obstacles. Meanwhile Andreas Gombert of the Fraunhofer Institute in Freiberg, Germany, has used the non-reflective coating found in moths' eyes as the inspiration for a sol-gel-based coating for solar cells. The coating increases the amount of sunlight that can enter the cell by more than 10%.