White paper inspired by beetles

Straits Times 13 Jun 09;

THE dazzling white shell of the Cyphochilus beetle has shown researchers how to use new techniques to produce brilliant white paper.

The beetle, which is found in South-east Asia, is believed to have evolved its white colouring as camouflage to help it blend in with local white fungi.

The work was done by minerals group Imerys Minerals and the University of Exeter in Britain.

In 2007, the team's research, published in journal Science, revealed how the beetle produced its brilliant whiteness using a unique surface structure.

New research, published in the journal Applied Optics, shows how some of the beetle's shell structure can be mimicked to produce coatings for white paper, said the university in a statement.

The beetle's scales are 1/200th of a millimetre thick, about 10 times thinner than a strand of human hair, it said. Good quality white paper would need coatings twice as thick to be as white.

The team found, however, that through careful mineral selection and processing, it is possible to mimic some of the structure of the white beetle's shell to produce an enhanced paper coating. This could lead to lighter paper that could be cheaper to produce and better for the environment.

'It is interesting to consider that clues found in a small, obscure beetle could find application in large-scale industry,' said Dr Benny Hallam, application support manager of Imerys Pigments for Paper Europe Technology Group.

The company is looking at producing the beetle-inspired white coatings on a large scale.

Colour in both nature and technology can be produced by pigmentation or by regularly arranged structures.

Whiteness, however, is created through a random structure, which scatters all colours simultaneously. The beetle's body, head and legs are covered in long flat scales which have two highly random internal 3-D structures.

The university is looking at the many different ways that animals and plants produce whiteness.

Said the university's Professor Pete Vukusic: 'Natural systems are packed with inspirational designs that have evolved to serve key biological functions. Developing scientific knowledge about where to look and then how to take technological or industrial insight from them is an increasingly important practice, especially in this financial climate.'

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