Biomimetics
- an interview with Janine Benyus
August 2002

Kevlar is one of the toughest materials humans can produce. But it is very demanding to produce. It involves heating petroleum to over 700 degrees celcius, and then, under an enourmous pressure in vats filled with sulphuric acid, dragging out long, thin fibres. Once made, though, it'll will last for 20.000 years in a landfill.
Nevertheless, kevlar is easily outdone by ordinary spiders' web. The spider silk thread is 5 times stronger than steel, and extremely elastic. But the production process is is rather less dramatic. The silk is produced in the abdomen of the spider, at room temperature and normal pressure, using flies and crickets as the main rawmaterial. There is no toxic waste and the silk is entirely biodegradable.

What if one could mimic the spider, using its methodes to create fantastic materials - without polution and consuming only a minimum of energy and rare rawmaterials?
Nature holds countless examples of solutions and materials that outperform human high technology by far. We are surrounded by systems more advanced than anything scientists and engineers can create - yet we hardly notice. We are not used to thinking of biology and living organisms as models of technological developments.

There's much to learn: The leaves of plants could inspire a new sort of solarpanel. The way cells kan read and copy the vast amounts of information in our genes may serve as a model for future tiny computers. And since a woodpecker can stand hammering holes in trees with its beak there might be a lesson to learn for someone constructing a crash helmet.

These are examples technological solutions that are completely different from usual engineering approaches, and they are living proof that it is in fact possible to create materials and processes that are far more effecient and elegant than todays' technology.
As added bonus, the examples of nature also show that highly advanced technology and sustainability compliment each other very well.

The term "bio-mimetic" is often used to describe technologies and systems that mimic natural solutions.
Velcro is a well-known example. The inventor got the idea for Velcro by studying the little hooks on the burrs that got stuck in the coat of his dog. The Eiffel tower is another example. The man who engineered it, Gustave Eiffel, drew on observations of bone structures and plant stems to create a strong and steady construction from a minimum of material.

A peacefull factory
In recent years scientists have started to notice more of the solution, that are right under their nose. Moderne technology has become so complex and the dimensions of electronics are increasingly so small, that some systems have started to resemble biology more than usual mechanical functionality of engineering.
Biotech, intelligent computers, nano-technology and managing enormous global systems are among the key technologies of the coming years. Following their development, one can't help notice how often scientist use terms and models from biology in order to understand and explain what they're working on. For instance, solutions are often said to be "evolved through survival of the fittest", and expressions like systems being "intelligent", "learning" or "adaptive" abound.

In 1997 Janine Benyus, an american biologist, published the book "Biomimicry" which has since become somewhat of a bible on the topic. Her book documents the efforts to mimic natural solutions in fields such as energy and electricity, computing, agriculture, smart materials and medicin. Benyus describes how a better understanding of the workings of nature and the principles of ecology could be the basis of securing humans a comfortable life without wrecking the environment.

It would be a world characterized by technologies created from a logic completely different from the technology of industrialism.
"imagine walking through a forest", says Janine Benyus: "You can think of it as this enormous chemical factory, with cellulose, bone, silk, all kinds of materials and chemicals being produced constantly. Water and nutrients are being distributed across miles of networks, and yet, it is happenling silently and you don't need to wear a hard hat, or eye or ear protection or ear protection. Llfe does its business in water and at life friendly temperatures.
In contrast, what we do in the iindustrial age can be summed up as "heat, beat and treat" and in the process we use chemicals and create noise and waste. Nature doesn't create waste, cause everything is connected in networkd, using and reusing materials over and over. A leaf falling in a forest and nobody noticing, that just doesn't happen. Someone will start eating it".

Peacock-paint
Most us have a sci-fi movie induced vision of the future as a world of glass and steel, with metallic robots and super-slick hovering cars. Janine Benyus' vision of the city of the future is rather different.
She imagines buildings that would function more like organisms, Their surfaces would collect sunlight and they would filter and draw their own water, using something similar to the rootsystems of trees. Houses would be different from locality to locality, reflecting exactly the weather and naturally available materials in each place.

Benyus imagines cars with bodies created from a material that mimics the structure of abalone shell. Mother of pearl consists of thin layers of soft and hard materialer alternating. This makes the material extremely impact resistand, and even if a crack should form, it would be stopped by the layered structure.
Rather than painting the car, one might decorate it in the same way that peacocks get their incredible tail feather. The feather are actually just brown, but the outermost layers works as a prism, scattering and refracting the light, which is how the clear and glittering colors emerge.

It seems likely that cars of the future will be powered by so called "fuel cells". Fuel cells can run on a wide variety of fuels, but the environmentally ideal would be using hydrogen.
When hydrogen is combusted the only waste product is water vapor. The problem, however, is producing enough hydrogen for all the cars of this world. Hydrogen is produced by cracking water - a process that requires as much energy as the energy which is released when hydrogen is combusted.
If oil, gas or coal powers the production of hydrogen then the environmental gains are to a large extent lost. So instead Janine Benyus imagines that one might mimic the processes which are used by every little plant leaf when it cracks water using sun light in order to grow - the proces is called photosynthesis.

Sustainability
The way Janine Benyus sees it, biomimetics is important not least because it presents a way to avoid a threatening ecological breakdown on the planet. There's a pressing need to develop technological solutions that won't strain the ressources of the earth further, but which rather can help restore and heal the destructions that the heavy handed methods of mankind so far have inflicted on the balance of nature, says Benyus.
She uses yet another example from biology to make her point:

"If you clear it out a patch of land, the first plants to move in are going to be annual plants or weeds, and they have a high through put strategy. The grow very quickly, they put their energy into plant bodies and into seeds - but not so much into roots. They don't really have a future in that spot. They are putting their energy into seeds, because they are moving to the next horn of plenty, the next open field. And that’s how we have been. We've basically been taking rawmaterials at a high throughput rate making products and waste and more people, and then we've moved on to the next colonized area. But conditions have changed in our world, There is no other place to go anymore, and because there are so many of us, we need to act more like a mature forest that settles into a place and begins to develop rather than grow"


Could pinguins and pine cones lead to better uniforms?
The feather coat of penguins is an extremely efficient insulation against cold. Like fur, the fluffy feathers insulate by trapping air. However, penguins get their food by diving for fish, and, considering all of the air held in the feather coat, one might expect that the penguin would float.
What actually happens when the penguin dives is that the air is pressed out of the feathers, so the coat collapses and the penguin becomes thin and streamlined.
When the penguin comes up out of the water again, the coat needs to inflate immediately, otherwise a wet penguin would be unable to survive at temperatures that are typically below minus 20 degrees celcius.
It turns out that penguin feathers consist of lots of little hooks - akin to those you find on velcro. The hooks mean that the feathers cannot slide in relation to each other. When they are compressed by the pressure of the water, they are bent, and like springs they jump back into shape the moment the penguin leaves the water.

The british military has sponsored research at the university of Reading to investigate whether that mechanism could be mimicked in order to create better uniforms and suits for extreme conditions.

Pine cones are another source of inspiration for that purpose. When cones are hanging on the tree, they are firm and closed. But as they ripen and fall to the ground, they open in order to release the seeds. This works because the scales of the cone consist of layers of two materials that react differently to humidity. When the cone dries out, the scales will bend, because one of its sides will expand more than the other.
In the project for the British military this was mimicked by creating a textile with lots of little flaps, which automatically open when the person wearing it starts to sweat. When the skin returns to it's normal humidity, the flaps will close again.


Goats' milk with spiders' web
Spiders' web is a fantastic material, and if it could be produced i sufficiently large quantities it would be ideal for a wide range of uses such as tennis racket strings, parachute wires or extremely tough fabrics.
Silk worms can be farmed by the millions, but spiders happen to be too individualist and aggressive for that.
Instead a canadian company called Nexia has managed to isolate the gene, which makes the spiders capable of producing their silk. The gene has been transferred to cells in the mammary glands of goats, with the result that the milk from these goats now contain the protein that spider silk consists of.
In addition Nexia has developet advanced machinery which can mimic very precisely the way spiders drag out of little nozzles in its abdomen the silk and spins it. It turns out that the exact treatment and stretching of the thread is crucial to the strength and flexibility of the silk.
So far Nexia has not succeeded in creating threads that are as strong as real spiders' silk. But if they achieve it, one of the first major costumers will be the American military, which plans to use the silk in a new type of bulletproof vest.

The use of genetic manipulation is controversial in biomimetic circles. Professor George Jeronimides who heads the institute for bio-mimetics at the university of Reading thinks of biology as an inspiration and a source of solutions. But to him, there's nothing wrong in exploiting that knowledge in completely different contexts and using whole other technologies than those found in nature.
On the contrary Janine Benyus considers genetic engineering to be a fundamental violation of natures principles. As she sees it, the point of bio-mimetics is to learn from nature - which also implies that you learn to stay away from technologies and solutions that don't occur naturally. If a technology is not used in nature, that to Janine Benyus is a clear warning that there are serious side effects and riscs.


Hairy paint
How do leaves and flowers keep so clean? A team of scientists from the university of Bonn set out to answer that question. One would expect that the leaves that had the smoothest surface would be best at staying clean, but it turned out to be the other way round.
The white lotus always has immaculately clean leaves, but a look at them through the microscope reveals that the surface is covered by tiny hair or needles. When dust falls on the leaf it gets stuck on the tip of those needles, and therefore it washes off easily when a raindrop rolls down over the leaf.
This effect was dubbed the "lotus effect" and the scientist proceeded to develop a new type of paint for house facades, which stays cleaner longer than ordinary paint. In Germany the paint is sold under the brand name "Lotusan" and it comes with a 5 year guarantee that the façade will stay clean without need for rinsing.
Next: paint for cars using the same principle.


Swimsuit ala shark skin
Shark skin is very rough, in fact dried shark skin can be used as sanding paper. The skin is covered by little V-shaped bumps, made from the same material as sharks' teeth. The rough surface has been shown to reduce friction when the shark glides through water, which is why sharks are surprisingly quick and efficient swimmers.
Mimicking this, the manufacturer of swimwear Speedo, has developed a swimsuit for competetions which has lots of little V-shaped scales. And it works: At the Sydney olympics 27 out of 33 gold medals in swimming were won by swimmers wearing the new suit.