Bristleworms engineer optics – Photon02

Computer and optical communications engineers are now using optical structures to produce faster, more powerful, light-based processors and networks. However, according to Dr Andrew Parker from Oxford University, they are well behind the times as nature has been making these optical structures for at least 515 million years. He and his team are now planning to unravel nature`s manufacturing process and use it to create man-made optical devices.

Speaking at the Photon02 Conference in Cardiff on Wednesday 4 September, Dr Parker will explain how his team discovered that the spine of a type of polychaete worm or bristleworm resembles the structure of photonic crystals, crystalline optical structures that can control and manipulate the path of light.

Bristleworms live on the sea bed. Some, such as the `Sea Mouse` found by the researchers, stand out due to their iridescent spine and hairs. It is this iridescent spinal structure that resembles the photonic crystals that high-tech industries are clamouring for. The bristleworm`s scaley spinal structure consists of an ordered array of holes made in the natural polymer chitin. It is so efficient at routeing light it has prompted Dr Parker`s team to begin investigating exactly how it was made.

The method that nature uses to produce these crystals is called molecular self-assembly. It involves the spontaneous formation of molecules into bonded, well-defined, stable structures. Dr Parker intends to work out exactly which molecules nature uses and the conditions under which they combine together to produce the photonic crystal. He said: “Animals don`t possess big design laboratories. They simply mix together chemicals, pass them through a series of environmental conditions, extrude them through nanopores and macropores, and out comes a perfect photonic crystal. I aim to crack this code of self-assembly.”

It is not just bristleworms that contain optical structures. According to Dr Parker nature has produced a variety of efficient optical designs through millions of years of evolution. Some such as the reflectors found on butterfly wings are already being used in commercial and defense situations. Dr Parker said: “Animals have a host of clever tricks, such as molecular rulers and counting machinery. They possess a great range of optical devices, from mirrors and anti-reflective structures to fibre optics and photonic crystal fibres. In some cases, the natural designs are novel to physics. Some have even been preserved in fossils, up to 515 million years old.”