A close-up view of Velcro, showing its hook-and-loop design. This design was inspired by the cocklebur.
Credit: Breger Dee
It might have started silently, or with a sound like that of bubbling mud. On the shores of a pre-Cambrian pond a cluster of molecules met, and together they lurched forth into this thing called Life. As mountains rose and crumbled and glaciers galloped across the Earth, Life scrambled to survive by being innovative.
Life learnt to harvest energy from the Sun and to transform it for work without creating toxic by-products. It dabbled in optics, flirted with aerodynamics and played around with neural networks. Later, it gave rise to Homo sapiens; it also invented cockleburs.
Then one day in the early 1940s, Georges de Mestral was walking his dog through long grass. Cockleburs attached themselves to the Swiss inventor's trousers and his dog's fur and — a consummate scientist — de Mestral became curious rather than annoyed.
Under the microscope, he noted the hook-and-loop system the seed cases had evolved for dispersal on the fur of animals. Bored to tears by the zipper, he was inspired.
Velcro — invented by de Mestral in 1948 — is probably the most famous example of 'biomimicry' or 'biomimetics', where technologists turn to nature for inspiration. It's certainly not a new idea: from Icarus' feathers to da Vinci's avian-inspired flying machines and the Wright Brothers' habit of studying vultures, people have long tried to emulate evolution's most spectacular outcomes.
But as the Earth heats up and we hurtle towards an energy and water crisis, there's a new imperative to taking notes from nature. "After 3.8 billion years of research and development, failures are fossils, and what surrounds us is the secret to survival," says Janine Benyus, U.S. biologist and author of Biomimicry: Innovation Inspired by Nature. Published in 1997, the book set off the latest wave of technology modelled on nature: its forms, processes and ecosystems.
According to Benyus, our ancestors were practised in the art of biomimicry. "I think it's an old impulse for humans to take their cues from other organisms," she says, referring to the native Inuit of Canada who copied the snow houses of polar bears to make igloos, and African tribes that found edible plants by observing the dining habits of chimps. "But lately we've become very enamoured of our own synthetic abilities."
Benyus thinks our drift away from nature started with the advent of agriculture: "When we broke free from the vicissitudes of hunting and gathering and learnt to stock our pantries, we fooled ourselves into believing that we didn't need other organisms at all," she says. Since then, the Scientific, Industrial, Petrochemical and Genetic Engineering Revolutions have repeatedly reinforced the idea that we're free from biological constraints.
In recent years, however, that illusion has been shattered by the spectre of global warming and the looming end to fossil fuel supplies. Since few of us would be willing to forgo the products and services we've grown accustomed to — food, water, shelter, lattes, plasma screens — the challenge becomes meeting the complex demands of civilisation within the bounds of sustainability.
Along with Benyus, a growing band of scientists, designers and engineers thinks that might be possible, if we turn back to nature for advice. "Life has learnt to fly, circumnavigate the globe, live in the depths of the ocean and atop the highest peaks, craft miracle materials, light up the night, lasso the Sun's energy and build a self-reflective brain," writes Benyus.
"Living things have done everything we want to do, without guzzling fossil fuel, polluting the planet or mortgaging their future. What better models could there be?"
THERE ARE NO BETTER MODELS, according to Tim Finnigan, a marine engineer at the University of Sydney. Start him talking about biomimicry, and the conversation turns to giant mechanical shark fins and towering forests of computerised kelp. These are not props from a bad sci-fi flick: they're Finnigan's designs for underwater power generators. In his quest to harness the world's waves and tides for renewable energy more efficiently, Finnigan has taken his cues from aquatic life.
Sharks are among the most efficient swimmers in the ocean. With their streamlined bodies and stiff, high tail-fins, they convert up to 90 per cent of the body energy they use for motion directly into forward thrust. Inspired by such thrifty hydrodynamics, Finnigan designed his tidal stream generator: an 18-metre-long biomimetic shark tail with a fin spanning 15 metres. Enough to humble even the most enthusiastic yum cha diner.
"Rather than have a body moving through a stationary fluid, we have fluid that's moving past a stationary body," says Finnigan. "We reverse the flow of energy, and use the tidal flow to drive the fin back and forth against an electrical generator." By mimicking the swimming motion of sharks, he hopes to approach their energy conversion efficiencies.
Then there's Finnigan's biomimetic forest of giant kelp. "As a diver I've looked at the way motions occur under water in the presence of waves," he says. "I see plants that move quite dramatically and yet they never seem to be pulled out, even in the most dramatic waves."
Designed to span water depths up to 45 metres, Finnigan's kelp-inspired wave energy generator raises a series of flexible blades from a hinge-point near the ocean floor. As it sways along with the whims of water motion, the device delivers energy to a generator near its base.
The trouble with conventional designs, according to Finnigan, is that they're made to stand rigidly against ocean forces. As a result, they must also be engineered to withstand the massive forces delivered during storms. "The structures we try to build in the ocean just never end up being strong enough — at low costs — to survive out there," says Finnigan. "So I looked at what does survive in the ocean, and what survives out there are the natural species."
In the manner of aquatic plants and animals, Finnigan's designs move in harmony with the forces of the ocean. They respond to changing current or wave conditions by reorienting to maximise energy capture. And in severe weather — to avoid a battering — his wave energy generator will lie flat against the ocean floor. "Just like plants, they're naturally adapted for survival," he explains.
With ocean testing planned for late 2007, Finnigan predicts that his generators will be on the market within three years. In the same way as turbines in a wind farm, they could be deployed in multiples to supply clean, renewable energy to coastal regions.
"Biomimicry is a powerful tool," says Finnigan. "Nature's energy conversion systems have been evolved and optimised over billions of years; people have only been making them for a few hundred."
Mick Pearce had similar thoughts when he started taking design advice from termites. While other architects were cursing the infamous chewing insects as mortal enemies, Zimbabwean-born Pearce was taking notes. Then, one day, among the ochre mounds that studded the savannahs of his homeland, he was struck by a remarkable idea.
Now, spanning half a block in the bustling business centre of Harare, the capital of Zimbabwe, stands Pearce's nine-storey tribute to his tiny but mighty mentors. The Eastgate Centre, a combined shopping centre and office block he designed in the early 1990s, was inspired by the architecture of termite mounds.
It turns out that the mounds are maintained at the critical temperature termites require for survival — a constant 30.5˚C, despite a daily temperature range of between 1.6˚C and 40˚C. Most impressively, this precise thermo-regulation is achieved through structural design.
"We were building office blocks for a client in Harare and we were running out of money for mechanical parts, and the cost of energy was getting higher and higher," says Pearce. "So we were looking for ways to see if we could make a building without air conditioning." Then Pearce realised the termites had beaten him to it.
Termites build their mounds using thick outer walls and a network of ventilation tunnels for thermo-regulation. Breezes entering at the base of the mound are mixed with water drawn from subterranean levels by the termites, causing evaporative cooling in the main chambers, before rising up and out through a central passage.
By analogy, the Eastgate Centre uses the concrete structure of the building and fan-driven air circulation for temperature control. Fans draw cool, fresh air from the atrium and blow it to higher levels through vents and hollow spaces between the floors. As it rises and warms, the air is blown out through funnels in the roof of the building.
With his termite-inspired cooling system, Pearce cut energy use to 10 per cent of the requirements of a similar air-conditioned building. But that's nothing, he says, compared with his latest project: Melbourne City Council's new Council House.
Opened in August 2006, the building — dubbed 'CH2' — uses only 15 per cent of the gas and 7 per cent of the electricity of the former Council House. And this time around his inspiration came from a different natural structure.
"The building itself moves and responds to light and energy like a tree," says Pearce. He points out the recycled timber facade that opens and closes in response to the Sun; the windows that mimic classic leaf morphology, decreasing in size from the ground floor up to capture sunlight in the city efficiently; the tap root that mines the sewer for water, which is then purified and used in the building's cooling system.
According to Pearce, the most important lesson we can take from nature is how to live using only energy from the Sun. "It's not just buildings — the whole social fabric will change when we shift our energy base."
"We let access to fossil fuels create huge social differences: it supplements human labour and gives enormous advantage to some people and not others," he says. "Until we start living by sunshine, we won't be a happy place."
Nature figured out how to live by sunshine a few billion years ago. Back then, cyanobacteria led the charge, followed by green plants. Today, in laboratories around the world, Homo sapiens are taking up the challenge laid down by our unicellular cousins.
Photosynthesis is the process by which energy from the Sun is used to convert water and carbon dioxide into carbohydrates and oxygen. Lettuce manages it with humbling ease. But, as the biochemists and biophysicists charged with the task have come to appreciate, the process — fundamental to life on Earth — is one of daunting complexity.
It requires such a broad range of expertise that in Australia and New Zealand, some 40 researchers from 11 institutes have collaborated to form the Australian Artificial Photosynthesis Network. "Harnessing the energy of the Sun as a renewable resource is just one aspect of the project," says Tony Collings, the group's cofounder and a research scientist at Australia's national science agency, the CSIRO. "Artificial photosynthesis can mean different things to different people."
He refers to the plethora of research efforts already underway, with each project focussing on the minutiae of the reaction: from light capture to water splitting to carbohydrate generation. At this stage, however, the most advanced area of research is in 'organic photovoltaics': technology that mimics the way plants convert sunlight into electrical energy.
In plants, energy from the Sun excites electrons in the green pigment chlorophyll and those electrons are passed between a series of electron carriers, eventually providing the energy to fix carbon dioxide into carbohydrates. Scientists are attempting to tap into that flow of electrons by using dyes as chlorophyll analogues. One of the photocatalysts being tested is titanium dioxide: the pigment commonly found in white paint.
According to Collings, it might one day be possible to make a photovoltaic material that could be painted-on in micron-thick layers and retouched every year, which isn't possible with current silicon solar cells. Organic photovoltaics also promise to be much more cost-effective and more efficient under conditions of low light or heat compared with current silicon technologies.
As the first leaf-inspired solar cells hit the market, Collings is careful to emphasise that the potential applications are much broader. "The idea is not only to displace some of our conventional energy with a renewable source," he says. "We're also going to try and produce a product at the end of it."
In plants, the products are carbohydrates. But by tweaking the catalysts and co-reactants, it should be possible to output a range of materials. These might include sugars for direct consumption, proteins for feeding humans and livestock, cellulose fibres for use in textiles, and even renewable fuels such as hydrogen and ethanol — though these are likely decades away.
Collings' personal photosynthetic preoccupation is a protein called rubisco, which he fondly describes as "a big, fat enzyme that's not very efficient and is buggered up by oxygen". In plants, rubisco's job is to facilitate the uptake of carbon dioxide and its conversion to carbohydrates. Its inefficiencies are largely due to atoms that waterproof the enzyme's active site — a hangover from the evolution of photosynthesis in the sea.
"What we hope to do is redesign it on the computer, stripping away some of the non-essential architecture," he says. Given that natural rubisco has an efficiency of only 1.5 per cent, even a fractional improvement would be a huge boost to production. "This is a massive undertaking," says Collings, "but the prize is invaluable".
That prize will be the ability to make carbon products more efficiently than plants — but not only because of Collings' synthetic rubisco. In nature, environmental variables like temperature, carbon dioxide and light availability also limit the rate of photosynthesis. In a laboratory, these variables can be optimised.
"Plants also tend to be very wasteful of water, because moisture escapes as carbon dioxide is absorbed through leaf pores," he explains. With water efficiency optimised, artificial photosynthesis could lead to a drier form of agriculture — a particularly valuable prize for drought-prone countries like Australia. And the savings could be monumental: "To make a kilogram of cotton, we currently use 4,760L of water," says Collings. "In principle, that ought to be one litre."
But Collings insists that we shouldn't get cocky about the prospect of improving on nature's efficiencies. "We don't have to pass on all this fantastic genetic information that plants have to. We don't have to cope with drought or frost from time to time. We can work in a laboratory with a highly controlled, specified set of conditions," he says. "In some respects, we're trying to do something a little bit easier than photosynthesis."
IMAGINE A FIBRE AS THICK AS A PENCIL that could stop a 747 passenger jet mid-flight. Spiders have been making it for millions of years and — to the chagrin of materials scientists everywhere — they've been making it from insects, at room temperature, using water as a solvent. Compare that with the energy-expensive, highly toxic production process for Kevlar — our toughest synthetic fibre, used for making bulletproof vests. To make Kevlar we drill for oil, dissolve petroleum products in hydrochloric acid heated to extreme temperatures and draw it out into a fibre under enormous pressure. And still the synthetic fibre falls short of the strength and elasticity of spider silk. No wonder there's no superhero named for Kevlar.
Now imagine that we could manufacture spider silk, and we could do it using the same environmentally benign process that spiders use. David Knight of the Department of Zoology at Britain's University of Oxford is working on it. He's managed to build a two-metre-long biomimetic pair of spider spinnerets. The device works by taking silk proteins from silkworms and imitating the physical and chemical process of spider spinning.
The next step, already underway in several laboratories around the world, is to synthesise spider silk proteins from scratch. There's just one problem. "The stuff that comes out of a spider's bottom is immensely tough and very stretchy," says Knight. "But as soon as it's wet, it loses a lot of strength." The trick will be to keep the amazing properties of spider silk in a fibre that can tolerate a rain shower.
Materials scientists are also envious of abalone. The mother-of-pearl lining their shells (calcium carbonate with intervening layers of elastic biopolymer) is twice as tough as the best hi-tech ceramics. And while we make ours in an energy-expensive, polluting process that engineers call "heat, beat and treat", the soft-bodied snail manufactures by self-assembly, at ambient conditions, without producing toxic wastes.
Inspired by the abalone's ingenuity, Jeff Brinker at Sandia National Laboratory in New Mexico is working on ways of making 'self-assembling' polymers. His strategy relies on the repellent and attractive forces between his precursor molecules and water. Using a water-hating surfactant and a water-loving solvent, he herds the two different types of molecule into a layered structure.
"The beauty of self-assembly is that these molecules will organise themselves into hundreds of layers without any external energy supplied by us," says Brinker. "If we can manufacture this efficiently in a process that's self-healing, then that looks very good for the future."
Benyus is equally optimistic about taking lessons from nature's engineers: "We're talking about high-performance materials made in completely different ways, in silent manufacturing processes at room temperature in water. That's the new finish line for our materials scientists."
In 2001 the World Heath Organisation launched its Global Strategy for Containment of Antimicrobial Resistance, describing the evolution of bacterial resistance to antibiotics as "a threat to global stability". Meanwhile, in temperate waters along the southeast coast of Australia, a gently swaying seaweed was keeping quietly bacteria-free.
Delisea pulchra keeps its fronds free of biofilms — the slimy colonies formed by bacteria when growing on a surface — by making chemicals called furanones that jam bacterial signalling systems: with their communications systems down, bacteria become unable to form and maintain a colony. This trick was brought to human attention a few years back by Peter Steinberg and Staffan Kjelleberg of the University of New South Wales in Sydney.
Along with a team of chemists, they've now developed synthetic analogues of furanones with the goal of recreating the seaweed's strategy in the biomedical field. At this stage, the technology is being trialled for the prevention of biofilm growth on contact lenses. The longer-term plan is to use the chemicals on medical implants and in pharmaceuticals.
According to Steinberg, the benefits of this appropriated technology to human health could be significant: research suggests that about two-thirds of human infections are caused by biofilms, and he thinks these furanone analogues might side-step the problem of bacterial resistance.
"The thing that drives the evolution of resistance is the intensity of selection pressure, and there is no greater, more intense selection pressure than trying to kill an organism, which is what all antibiotics and current biocides do," he explains.
"The molecules we make are actually signal molecules, so all we're doing is telling the bacteria 'don't settle here', which is a very important distinction. We think that reduces the likelihood for evolution of bacterial resistance to these chemicals." If he's right, the habits of a humble seaweed could help avert a global health crisis.
On the bank of a river, among the fruity smell of wet wood, a suite of organisms feeds, burrows, breathes, excretes, makes love, breeds and dies. It's a miniature soap opera and Dean Cameron has borrowed the script to help conserve energy and water resources. His wastewater treatment system, Biolytix, is designed to replace sewerage connections by mimicking the ecology of a river bank.
"A river will naturally cleanse water," says Cameron, who trained in botany and ecology before "becoming obsessed" with wastewater treatment and establishing a company in Maleny, northwest of Brisbane. "If organic pollutants are added, within a kilometre or so you'll generally find all of those pollutants will be removed."
Conventional wisdom held that aerated water and microbes did the job. This paradigm resulted in wastewater systems that needed high-energy inputs to dissolve oxygen, which is relatively insoluble.
"But nature doesn't do it that way," says Cameron, explaining that when organic material falls into a river, it quickly becomes buoyant with fermentation gases and collects along the river bank. He thinks most decomposition occurs at the river edge, rather than in the river itself.
Enter the main players in Cameron's story: a menagerie of worms, beetles, mites, flies, fungi, protozoa and bacteria. On a river bank, when there's decaying to be done, they form a predictable succession. But mimicking that species assemblage is only part of the challenge. Even more critical, perhaps, is recreating what Cameron calls "the architecture of decomposition".
He explains it with a certain degree of relish: the way worms forge a honeycomb pattern in material early in the breakdown process, excavating a network of interconnected pores in the cabbage, cowpat, carcass … the pattern, he says, is always the same. "It's very similar to the alveoli [air-sacs] in the lungs, and it's there for the same reason — you've got to get oxygen into the material in order for the aerobic organisms to break it down."
This structure also allows drainage of further wastewater through the system, and, in this way, converts the decaying matter into a filter. "That's the sort of smart engineering that nature's been working on for a very long time," says Cameron. "Taking waste material that's a problem and turning it into the solution."
Food scraps, sanitary items, wastewater, sewage: all that muck and more passes quickly and quietly through the guts of Cameron's river bank (which is typically housed in an underground tank) through a fabric filter, and out the other end as water suitable for irrigation.
The technology — which is currently servicing homes, hotels and resorts around the world — reduces domestic water consumption by up to 50 per cent, while requiring a mere 10 per cent of the energy of typical aerated-treatment plants.
Cameron's vision is to inspire a widespread shift away from centralised water treatment. "About 80 per cent of the cost of a sewage treatment plant is just to move the waste from A to B," he says, describing the traditional method of dealing with human waste. "Nature treats waste in a decentralised manner. Wherever it's produced, that's where it's treated and that's where the nutrients and water are recycled. We could sure take some tips from nature."
It might seem counterintuitive to liken an oil refinery to an orchid. But in the biggest and most coordinated form of biomimicry, enterprises are acting like canopy trees, shade plants, epiphytes, fungi, soil fauna and micro-organisms. Welcome to the emerging field of industrial ecology, in which industry looks to nature as a model for optimal energy and material flows.
Central to the idea is changing the linear nature of industrial systems — in which raw materials are used, products made, and by-products disposed of — to a cyclical or closed-loop system that mimics the resource efficiency of an ecosystem. So, just as in a forest, desert or coral reef, the by-product of one organism or process becomes the food or raw material for another. This not only gleans maximum economic value from a resource, it also minimises the flow of waste to the environment.
"The concept of industrial ecology is still evolving and different people view it in different ways," says Rene van Berkel, research coordinator for the Centre for Sustainable Resource Processing, a groundbreaking collaboration between industry, government and research institutes in Perth, Western Australia. "But the end result might be economic and environmental sustainability."
In the past few decades, a handful of industrial areas modelled on the concept have sprung up around the world. Perhaps the earliest to flourish was Kalundborg Industrial Park in Denmark, where a coal-fired power station and an oil refinery exchange waste steam, waste heat and waste water among themselves and neighbouring industries, thereby cutting annual greenhouse gas emissions by thousands of tonnes and reducing water consumption by 25 per cent.
This exchange of by-products and sharing of utilities between enterprises is referred to as 'industrial symbiosis' or 'industrial synergy', and is the key to industrial ecology. Successful symbioses at Kalundborg and elsewhere in the world are characterised by geographic proximity of the industries, a diversity of enterprises (think biodiversity), open communication, and some commercial advantage to the industries involved (think selective advantage) — though this may be indirect, such as improved community relations (think reciprocal altruism).
In terms of the number of synergies it hosts, Kwinana Industrial Area in Western Australia is a leading example of industrial ecology internationally. Established in the 1950s on the shores of the Cockburn Sound, 40 km south of Perth, it covers an area of about 120 km2, and is dominated by heavy process industries, chemical producers and utility providers. A recent study by the centre identified an unprecedented 48 industrial symbioses at Kwinana, compared with Kalundborg's 15.
The Kwinana Water Reclamation Plant, for example, takes secondary treated effluent from a nearby wastewater treatment facility, applies further filtration, and produces industrial process water for use by four local industries. This replaces water that used to be drawn from the public supply, which amounted to almost three per cent of the water available to drought-affected Perth.
In an example of energy recycling, the Kwinana Cogeneration Plant produces all process steam for the BP oil refinery and generates electricity for the refinery as well as for the grid. In return, BP supplies excess refinery gas to supplement the natural gas that is used for firing the cogeneration plant.
One of the latest symbioses announced for Kwinana, in June last year, is targeted at reducing greenhouse gas emissions. Wesfarmers CSBP, a chemical and fertiliser manufacturer in Western Australia, will supply carbon dioxide from its waste stream to Alcoa, an alumina refinery. Alcoa will use the carbon dioxide to reduce the alkalinity of its bauxite residue, thereby lowering the environmental risks associated with its products and locking up greenhouse gases at the same time.
However there are significant challenges to establishing industrial symbioses, according to the centre's van Berkel. "There needs to be a level of trust and understanding between the companies before they can start using one another's waste streams," he says. Legislation and community attitudes can also pose a barrier: by-products classified as 'hazardous waste' are stigmatised, and the costs for meeting regulatory provisions can be prohibitive.
At Kwinana, as in most industrial areas, successful symbioses have been the result of gradual evolution rather than grand design. The challenge now is to implement industrial ecology principles at the planning stage. Until we find greener ways to meet our energy and resource requirements, it can't hurt to make oil refineries a little bit more like orchids.
Julian Vincent is the director of the Centre for Biomimetic and Natural Technologies at Britain's University of Bath. His job, as he describes it, "is to sort out the interface between biology and engineering". One of the ways he's doing that is by creating a searchable database of the various methods that nature uses to solve engineering problems. After barely "scraping the surface", he's already compiled 2,500 examples, from the way a woodpecker makes a hole in a tree to the way a beetle draws water from the air.
His vision is to create a tool that will revolutionise engineering by making the suite of biological solutions immediately accessible to engineers at the planning stage. At the moment, Vincent estimates there's a 12 per cent overlap between the way nature and engineers solve problems.
He thinks our best hope for a sustainable future is to broaden that intersection as far as possible. "Biology makes do with energy from the Sun and everything it uses is recycled," he says. "It's coming at engineering from a very different point of view."
It's a perspective that we need to adopt out of necessity, according to Benyus. As the Earth heats up and analysts forecast global conflict over dwindling freshwater supplies, it becomes more and more difficult to ignore the reality of our biological constraints.
"Nature's technologies have evolved to be sustainable," says Benyus. "So now we're realising that not only can these organisms provide us with beauty, solace and wonderful goods and ecosystem services, but they can also — if we're humble enough — provide us with advice."
From this worldview, the protection of biodiversity takes on new meaning: it's a way of conserving a wellspring of good ideas.
Erica Harrison is a Sydney-based freelance writer and photographer.
