Joined: 16 Mar 2004
|Posted: Fri Feb 01, 2008 4:27 pm Post subject: How Nature is Helping Scientific Ideas to Fly
|What is the connection between the Blue Morpho butterfly, a dazzling creature found in the jungle canopies of South America, and a new form of radio frequency identification (RFID) tag called Omni-ID, developed in the UK? The answer is "biomimetics", the application to technology of designs and processes found in nature.
You may be unfamiliar with the term, but you will certainly be familiar with its benefits - Velcro was invented after Swiss engineer Georges de Mestral took his dog for a walk in the Alps and wondered how cocklebur seeds became stuck to the animal's fur.
That was in 1941. Today, some scientists and engineers are predicting a new wave of success stories for biomimetics. "Biomimetics has come of age," says Martin Kemp, a materials scientist and independent consultant. "In the past 10 years, our understanding of nature and our ability to mimic it have improved exponentially."
Researchers are using nature both as a freely available source book of ideas and as a way of solving some thorny functional problems. The Omni-ID tag, for example, has allowed companies to overcome one of the biggest difficulties with RFID, a radio technology used for identifying and tracking goods as they move through the supply chain. That problem is the inability to read tags that are in close proximity to metals and liquids.
According to Qinetiq, the UK defence technology company that designed the Omni-ID tag, this is particularly troublesome for retailers that use RFID technology.
"This has been a big issue for many companies, especially supermarkets," says Chris Lawrence, head of Qinetiq's Smart Materials Group and the lead developer of the technology. "If you try to put a traditional RFID tag on a carton of milk, a bottle of wine or even a box of cigarettes with foil wrapping inside then either you won't get a signal or you'll get one that's so erratic you can't trust it," he says.
He explains that the signal of an RFID reader can be distorted by metals and liquids, but an Omni-ID tag will reflect this signal back in strengthened form, ensuring it will always be readable.
The tag's secret is in its structure, an intricate arrangement of metal layers and gratings that affect radio waves in the same way that the Blue Morpho's wings affect light.
The project originated in the late 1990s when Qinetiq was still a part of the Defence Evaluation & Research Agency, the research and development arm of the Ministry of Defence. As DERA prepared to enter the private sector, its scientists and engineers were encouraged by the MoD to explore their "wilder and wackier" ideas, Mr Lawrence says.
"We had traditionally looked at very specific problems and they wanted to get us thinking more widely."
At the time, Peter Vukusic, a friend of Mr Lawrence's from his undergraduate days, was at Exeter University, trying to establish how the Blue Morpho was able to produce colours of striking brightness and iridescence.
"He was doing this research without funding," Mr Lawrence says. "So we part-funded him in conjunction with the BBSRC [Biotechnology & Biological Sciences Research Council]."
The butterfly's wings are covered with tiny scales containing structures known as multi-layers and diffraction gratings.
"People knew there were strange structures in there but they didn't know about the fine details," Mr Lawrence says, explaining that an electron microscope was needed to distinguish them. "What we did differently was to look at individual scales, each about 100 microns wide - just thicker than a human hair."
The properties of the structures were already well-known: multi-layers produce the iridescence in soap bubbles, for example, while diffraction gratings produce similar effects in metallic wrapping paper. However, says Mr Lawrence: "We hadn't thought of combining them . . . That's how it is in biomimetics; it's not generally about finding something new, it's about combining things in unexpected ways."
Using plastics and resins,Qinetiq was able to replicate the structures at a larger scale and to mimic some of their effects. Omni-ID was born when they decided to synthesise the structures using metals and found they could use them to concentrate radio waves in the bands used by certain RFID tags.
Mr Lawrence prefers to use the term "bioinspiration" rather than biomimetics to describe the process: "If we'd slavishly tried to copy what the butterfly had done then we wouldn't be here. It was looking at the mechanisms in the broadest sense, and inferring what could be done, that got us here."
Omni-ID tags are already in commercial use. Mining company BHP Billiton is using them to help manage its tool inventory at an open-cast mine in Australia; an international automotive company has bought "several tens of thousands" with which to track parts; and a large UK dairy has been using them to track roll-cages full of milk for the past year.
In another example, scientists at the Nees-Institut for Plant Biodiversity at the University of Bonn, have used their research into the structure of the lotus leaf - renowned for its ability to stay clean in muddy or polluted conditions - to create a "self-cleaning" paint for exterior surfaces.
Materials scientist Martin Kemp, who used to work at Qinetiq, says nanotechnology should soon produce a surge of further biomimetic innovation be-cause "nature is at its most smart at the nano-level."
This was one of the findings of a scientific mission on biomimetics led by Mr Kemp in January, in which a small group of biomimetics specialists, plus senior executives from industry, visited companies and research institutions in Germany and the Netherlands.
Geoff Hollington, a member of the mission and a product designer with a client list including Parker and Gillette, says he was particularly impressed by the nanoscale work of the "Evolutionary Biomaterials Group" at the Max Planck Institute in Stuttgart.
"They spend all their time looking at the surfaces of small animals, usually insects," he says. "What they've discovered is that different parts of these surfaces can exhibit very different behaviours, even though they're made of the same material. For example, different parts of an insect can be sticky or non-sticky; hydrophilic or hydrophobic; absorbent or reflective to light. All this is achieved with microstructures."
The use of one material to perform several tasks is one of the guiding principles of biomimetic research, Mr Kemp says. "It has tremendous advantages from both an ecological and a cost point of view: nature uses very little energy to make its materials; we use enormous amounts."
However, there is a more fundamental reason why designers should regard biomimetics as an essential part of their "tool-kit".
As Mr Hollington puts it: "Nature has been busy for a hell of a long time. It has made millions of mistakes and discarded them along the way so that all we see is the sum of its successes. Biomimetics means taking advantage of a near-infinite number of prototypes."
Copyright The Financial Times Limited 2007
Story posted: 1st May 2007