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If you have a problem, chances are, nature has already solved it better than you ever could. Dan Cossins looks at biomimetics

A dawn fog rolls across the hot, arid sands of the Namib Desert on Africa’s southwest coast. In the dim morning light, a Namib beetle scurries up a dune and spreads its wings against the breeze. As the fog condenses on the stiff wings, minute water droplets appear, before growing heavy enough to trickle along the surface and into the beetle’s mouth. This life-sustaining drink is vital because the beetle will absorb nothing but blistering heat once the Sun has risen.

The crustacean-inspired Robolobster is sent to
sweep the seabed for mines

In desert fogs, the droplets measure just 0.025mm across, small enough to be carried horizontally on the wind. But the Namib beetle has a clever trick up its sleeve, which has caught the attention of scientists who want to know this industrious insect’s secrets. “The beetle’s device is incredibly elegant,” says Dr Andrew Parker, a zoologist at the University of Oxford who studies how animals are adapted to extreme environments. “Large droplets form on its wings by virtue of their bumpy surface.” An intricate patchwork of water-attracting bumps and water-repelling channels moves the droplets like a bead of rain on the roof of a freshly waxed car – and the best thing, at least for humans, is that the process can be copied.

Parker was able to replicate the beetle’s microscopic checkerboard with synthetic materials. Now, the same principles could lead to self-cleaning surfaces, fog-clearing devices and solutions to water scarcity in the world’s driest countries. “It turns out we can recreate these properties quite easily with materials we already know about,” says Parker. “But we would never have thought of it without the inspiration we gained from biology.”

The natural world is an abundant source of ideas, and Parker isn’t the only one who sees the potential. In the burgeoning field of biomimetics, biologists, chemists and engineers are applying their understanding of natural design to the innovation of exciting new technologies. Billions of years of evolution have produced efficient solutions to the problems facing life on Earth and the challenge for the world’s leading biomimetic researchers is to identify and emulate the most useful.

Inspired by nature

“Biomimetics is about looking to biology for technical solutions,” says Professor George Jeronimidis, Director of the Centre for Biomimetics at the University of Reading. “It’s really an abstraction of good design from nature; design that can be translated to provide answers to some of the biggest problems we face.”

Andrew Parker has already drawn inspiration from the eye of a prehistoric fly to produce a new light-capturing material for super-efficient solar panels. Elsewhere, the unique underwater communication method employed by dolphins is being emulated to develop a tsunami early-warning system; the hair-like nanostructure of the gecko’s foot is being copied to create climbing robots and biodegradable medical adhesive; and the swift’s ability to change the shape of its wings could lead to faster, quieter and more agile planes. Even by solely focusing on insects, the opportunities are endless. Glow-worms produce light with almost no energy loss, bombardier beetles shoot boiling-hot chemicals at predators… the list could go on.

Drawing on nature for inspiration is not a new concept, however. Leonardo da Vinci designed planes like the wings of birds and, more recently, a domestic pet inspired the ‘cat’s eyes’ that now line our roads. The most famous example is Velcro, dreamed up by George de Mestral in 1941 after he observed how the tiny hooks on the spines of burrs clung to his dog’s fur.

But it is only now that technical capabilities are catching up with academic pipe dreams. Thanks to nanotechnology, electron- and atomic-force microscopes are unlocking the secrets of natural design. “We’ve seen huge developments in measuring techniques that allow us to analyse biology at an extremely local level,” says Jeronimidis. “These instruments have opened up opportunities to understand the structures and processes responsible for the exceptional properties seen in biology.”

Identifying these properties is one thing. Replicating them, however, is quite another. Molecule by molecule, nature is able to manipulate the simplest of ingredients to make fantastically sophisticated materials and structures. There have been notable successes, particularly in mimicking the shapes seen in nature. Boxfish and kingfishers, for example, have been imitated to make more aerodynamic cars, which are faster and more fuel-efficient. But imitating processes is more difficult, even for the most skilled of nano-engineers.

"Biomimetics is really an abstraction of good design from nature, design that can be translated to provide answers to some of the biggest problems we face"

Nano-engineering

Work on the Namib beetle’s water-collecting wings proves how complicated it can be. To produce a synthetic equivalent, Professor Robert Cohen, a chemical engineer at MIT, first applies layers of charged polymers to make a sheet of glass more absorbent. He adds silica nano-particles to create a rough texture to trap water droplets. This surface is then covered with a water-repellent Teflon-like material, before a water-attracting pattern is laid on top with a solution of charged polymer molecules.

The result is a versatile material that attracts and captures water before channelling it in a given direction. “We can use inkjet-style printing techniques to throw down any pattern,” says Cohen, who is adapting similar techniques to create a fog-busting material for airport runways. “There could be a lot of applications we haven’t even thought of yet.”

Some of the most promising bio-inspired innovations are proving more challenging because nature’s molecular jigsaws cannot always be replicated. The abalone sea snail, for instance, creates armour as tough as Kevlar from little more than calcium carbonate (chalk). It does this by manipulating proteins, coaxing them into thousands of irregular layers of tiny calcium carbonate tiles. The tiles are held together with a positively charged protein adhesive, strong enough to bind them but weak enough to let the layers slip apart to absorb the energy of a heavy impact. The military is keen to employ such structures in armoured surfaces, but the world’s leading researchers cannot yet match such subtlety at this scale.

Even more challenging is spider silk, a natural elastic material with a greater tensile strength than steel. A light, flexible, super-strength fibre like this could revolutionise everything from surgery to military armour – so it’s no surprise biotech companies are trying to replicate it.

Oxford Biomaterials, a company led by Professor David Knight, a zoologist at the University of Oxford, has attempted to mix the raw ingredients combined in the spider’s abdomen and spin the resulting solution into fibres to help repair wounds, torn ligaments or tendons, and even damaged nerves. “Spider silk has a whole range of useful properties,” Knight says. “And we’re not too far off replicating some of them.”

Researchers can already genetically engineer bacteria to make the correct proteins for spider-style silk. The real challenge is to develop a device that replicates the way a spider blends those proteins during the spinning process. Spinning artificial fibres involves the fusion of polymer molecules using chemicals or heat, but the spider is able to do it without either high temperatures or toxic solvents.

Despite all the possibilities, such obstacles mean biomimetics has so far led to few products. Some blame the difficulties of coordinating work across academic disciplines; others point to the short-term profit requirements of industry. “There is still a huge gulf between identifying something that could be useful and actually producing something,” says Andrew Parker, whose own research has led to a number of patents and commercial collaborations.

"Our clients give us a problem to solve and we filter through the ocean of biological literature, right through from amoeba to zebra"

Bringing biomimetics to market

Getting biomimetic products to market may be difficult, but some are dedicated to bridging the gap between research and commercial output. In 1998, Janine Benyus co-founded the Biomimicry Guild, a ‘consultancy for bio-inspired design’ where biologists work with corporate clients such as Boeing, Procter & Gamble, Nike, O₂, and Hewlett-Packard to develop innovations based on observations of the natural world. “Our clients give us a particular challenge to solve and we filter through the ocean of biological literature, right through from amoeba to zebra,” says Benyus. “Then we take them through the design process. We reduce the problem to the function level, find the best natural models and try to emulate them.”

Benyus believes the next century will produce technologies just as efficient as the natural structures that inspired them. With advances in nanotechnology continuing to open up new opportunities, bio-inspiration has the potential to revolutionise the way we do almost everything, from storing information and making materials, to growing crops, harnessing energy and healing ourselves. Using nature as a model will lead to exciting developments in engineering, architecture and medicine. It could also furnish us with innovations that help to save the habitats of the very plants and animals that inspired them.

But biomimetics has the potential to go even further – to turn science fiction into reality. If we can copy and adapt the ways animals crawl, swim, climb and fly, we can create robots to better explore internal organs, the depths of the oceans and distant planets. If we can learn how living organisms build and repair themselves, we can build self-repairing spacecraft and skyscrapers.

Who knows, if we can successfully replicate the adhesive qualities of gecko’s feet and the silk-spinning secrets of spiders, we could all be scaling buildings and swinging through the city like Spiderman.

Dan Cossins is a Bristol-based journalist

Body Armour

The world’s most sophisticated soldiers seek protection from a fish

The grey birchir knows how to look after itself. This African freshwater fish is protected by some of the best natural armour known to man and it’s inspiring the next generation of combat gear. Although they are made of ceramics, the fish’s multi-layered scales don’t shatter on impact and are flexible enough to keep the animal mobile.

Researchers at MIT studying the scales found that any cracks are localised around the point of impact instead of spreading outwards. “The fracture is localised because of the specific thickness and sequence of the different layers of scales,” says Professor Christine Ortiz, at MIT’s Institute of Soldier Nanotechnologies. “By replicating this multi-layer design, it may be possible to create an integrated suit based on the fish scale principles.”

Military scientists are attempting to recreate the properties of the grey birchir to produce a material that can withstand multiple penetrating impacts, yet remain light and flexible enough for dynamic movement. Essentially they are trying to create a bulletproof t-shirt.

A full body suit based on the grey birchir’s scales would offer increased multi-hit protection yet be 20 per cent lighter than single-layer equivalents. “The ideal body armour would be lightweight and provide protection against everything from bullets and improvised explosive devices, to chemical and biological weapons,” says Ortiz. The real challenge comes when trying to make that happen.

One approach that is currently being explored is self-assembly, a process in which molecules carefully choreograph themselves into formation as a result of thousands of tiny chemical reactions. As you might expect, this is extremely difficult. “No-one has yet been able to self assemble an entire complex three-dimensional microscopic structure similar to fish scales,” says Ortiz. “But the idea is to tailor the chemistry of molecules so they join together in a specific way.”

And, as the fish regenerates scales within two months of losing them, this could also lead to self-healing armour.

Nature's patents

Engineering

Animals have evolved to maximise efficiency of movement and are inspiring aerodynamic designs for faster, more fuel-efficient vehicles. Daimler, for instance, has developed a car based on the surprisingly streamlined shape of the boxfish. The people behind the high-speed Shinkansen Bullet Train reduced the noise-clap produced as the train emerged from a tunnel by copying the shape of a kingfisher’s beak, which helps it dive into water with very little splash.

Elsewhere, aerospace engineers at the University of Bristol are mimicking the healing processes found in nature to create aircraft that mend themselves automatically during flight. Similar to how a scab stops bleeding, a hardening epoxy resin is released from embedded capsules to seal any crack and restore the plane’s structural integrity. The researchers are also working with an aerospace composite manufacturer to develop a system where the healing agent moves around the plane as part of an integrated network. In the future, self-healing spacecraft could allow humans to spend much longer periods of time exploring far-flung planets.

The ultra-streamlined boxfish (top) and
the Daimler car it inspired (below)

Robotics
Lessons learned from eons of evolution are helping to produce robots designed to perform a multitude of tasks. Researchers at Northeastern University, Massachusetts, have already created underwater mine-sensing robots based on the neurophysiology of the freshwater lobster. German engineer Frank Kirchner has constructed a scorpion-inspired robot that can descend steep cliffs, climb rough terrain and squeeze into previously inaccessible areas. NASA hopes to use his robot in planetary exploration. At Stanford University, researchers are developing a climbing robot by mimicking the gravity-defying locomotion of the gecko lizard. It’ll be years before it can match the speed and dexterity of a gecko, but StickyBot can walk up glass and US defence research agency DARPA hopes it will one day climb up buildings to monitor the terrain below. And scientists at the University of California are attempting to create a surveillance robot based on the way a blowfly hovers and flies with incredible agility by controlling the exact shape in which its wings beat.

Architecture
The world’s leading architects are looking to nature to inspire a new generation of environmentally-friendly buildings. The Arab World Institute in Paris has a pattern of mechanically controlled, eye-like apertures on its south-facing façade. They open and close at regular intervals to control the amount of light entering the building, thereby regulating the internal temperature. Despite its misleading nickname, the ‘Gherkin’ (aka the Swiss RE building) in London actually resembles the glass sponge. Its lattice structure draws in air at the bottom and allows it to rise through spiral atriums as it warms, just as a sponge extracts nutrients as water is circulated upwards.

The Eastgate Centre in Harare, Zimbabwe, is modelled on termite mounds, which regulate airflow to maintain temperature by constantly opening and closing a series of vents. Architect Mick Pearce replicated this with a series of openings, ducts and fans placed throughout the building. His creation uses just 10 per cent of the energy that a conventional building would.

Environment
Bio-inspired designs are providing solutions to some of the most pressing environmental concerns, so plants and animals could furnish us with the means to save the very habitats in which they thrive.

Mark Clark, a professor of environmental engineering at the University of Illinois, has developed membranes for water treatment by incorporating the water-channelling proteins found in kidneys into synthetic systems. These new membranes are over 10 times more effective at rejecting salt than current desalination techniques and could revolutionise water purification in semi-arid coastal regions.

Meanwhile, the flippers of a whale that washed up on a New Jersey beach inspired the development of quieter, more efficient wind turbine blades. The bumps on the leading edge of a humpback whale’s flipper help it make tight turns, crucial for hunting schools of herring. Frank Fish, a professor at West Chester University in Pennsylvania copied these ‘turbercles’ to create serrated turbine blades that use 20 per cent less energy to generate wind power.

Medicine
From wound healing to drug delivery, nature is leading to new life-saving technologies. Engineers in Japan are building a hypodermic needle based on the way mosquitoes penetrate skin. Seiji Aoyagi at Kansai University in Osaka found that a mosquito’s stab is painless because its serrated proboscis minimises nerve stimulation by leaving only small points in contact with skin tissue. By etching slices of silicone dioxide into a similar shape, Aoyagi hopes to manufacture a hypodermic needle that causes no pain.

Here in the UK, a company called Cambridge Biostability has created heat-stable vaccines that can be transported and stored without refrigeration. The idea is inspired by the ‘resurrection plant’, which survives droughts by producing glass-forming sugars to preserve its cells in suspended animation. When water becomes available, the sugar-glass dissolves and the plant comes back to life. Scientists have replicated these glass-forming sugars to protect the active ingredients in vaccines, which are then released upon injection.

Find out more

100 great designs and ideas from nature www.n100best.org
The Biomimicry Guild www.biomimicry.net
Biomimicry: Innovation Inspired by Nature, by Janine M Benyusn (CRC, 2005)

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The Car of the Future