Biomimetics E-Book

Brian Clegg

• Herausgeber: Icon Books
• Kategorie: Wissenschaft und neue Technologien
• Sprache: Englisch
• Veröffentlichungsjahr: 2023

Seitenzahl: 206

Beschreibung

An exploration of the transformative ways in which nature has inspired the technological advancement of humankind. Biomimetics literally means emulating biology - and in a broader sense the term covers technological advances where the original inspiration came from nature. The Earth is a vast laboratory where the mechanisms of natural selection have enabled evolutionary solutions to be developed to a wide range of problems. In this new title in the Hot Science series, science writer Brian Clegg looks at how humans have piggybacked on natural experimentation, redeploying a solution to create things that make our lives easier. He looks at how the hooks on burdock seeds inspired the creation of Velcro, how the stickiness of the feet of geckos and frogs has been used to create gripping surfaces, such as tyre treads, and how even the most basic optical enhancement in the form of spectacles is itself a form of Biomimetics.

Leseprobe

Hot Science is a series exploring the cutting edge of science and technology. With topics from big data to rewilding, dark matter to gene editing, these are books for popular science readers who like to go that little bit deeper …

AVAILABLE NOW AND COMING SOON:

Destination Mars:

The Story of Our Quest to Conquer the Red Planet

Big Data:

How the Information Revolution is Transforming Our Lives

Gravitational Waves:

How Einstein’s Spacetime Ripples Reveal the Secrets of the Universe

The Graphene Revolution:

The Weird Science of the Ultrathin

CERN and the Higgs Boson:

The Global Quest for the Building Blocks of Reality

Cosmic Impact:

Understanding the Threat to Earth from Asteroids and Comets

Artificial Intelligence:

Modern Magic or Dangerous Future?

Astrobiology:

The Search for Life Elsewhere in the Universe

Dark Matter & Dark Energy:

The Hidden 95% of the Universe

Outbreaks & Epidemics:

Battling Infection From Measles to Coronavirus

Rewilding:

The Radical New Science of Ecological Recovery

Hacking the Code of Life:

How Gene Editing Will Rewrite Our Futures

Origins of the Universe:

The Cosmic Microwave Background and the Search for Quantum Gravity

Behavioural Economics:

Psychology, Neuroscience, and the Human Side of Economics

Quantum Computing:

The Transformative Technology of the Qubit Revolution

The Space Business:

From Hotels in Orbit to Mining the Moon – How Private Enterprise is Transforming Space

Game Theory:

Understanding the Mathematics of Life

Hothouse Earth:

An Inhabitant’s Guide

Nuclear Fusion:

The Race to Build a Mini-Sun on Earth

The Science of Music:

How Technology has Shaped the Evolution of an Artform

Hot Science series editor: Brian Clegg

Published in the UK and USA in 2023 by

Icon Books Ltd, Omnibus Business Centre,

39–41 North Road, London N7 9DP

email: [email protected]

www.iconbooks.com

ISBN: 978-178578-989-2

eBook: 978-178578-988-5

Text copyright © 2023 Icon Books

The author has asserted their moral rights.

No part of this book may be reproduced in any form, or by any means, without prior permission in writing from the publisher.

Typeset by SJmagic DESIGN SERVICES, India.

Printed and bound in the UK.

For Gillian, Chelsea and Rebecca

ABOUT THE AUTHOR

Brian Clegg’s many books include Dice World and A Brief History of Infinity, both longlisted for the Royal Society Science Book Prize, and, most recently, Ten Days in Physics That Shook the World.

CONTENTS

Acknowledgements

1Better by Nature

2Evolution and Technology

3Materials (Sticky or Otherwise)

4Pharmacopeia and Food

5Structures, Shapes and Networks

6Optics

7The Copycat Trap

8Facts and Futures

Further Reading

ACKNOWLEDGEMENTS

My thanks as always to the team at Icon Books, notably Duncan Heath. Thanks also to the companies and individuals who responded to my enquiries about their biomimetic products and concepts – you will find them detailed in the book.

BETTER BY NATURE

1

The way that humans interact with and change the world around us is so different in scale from most other organisms that it can be easy to forget that we are indeed animals that have evolved within nature, rather than existing separately as strange alien beings that have no connection with the world around us.

Of course, our ability to go beyond our natural limits using technology has transformed Homo sapiens from being just another great ape to the dominant species on the planet. We have managed to transcend the limitations of our preferred environment to make our lives longer, safer and more enjoyable than nature allowed. Technology has enabled us to do everything from gaining an understanding of the universe to travelling around the world and reducing the impact of a virus pandemic. At a more basic level, we can keep dry when it rains, warm when it’s cold and provide food for far more humans than the environment would naturally sustain.

These days we are used to hearing about the downside of human existence. We berate ourselves for the negative impact we have had on the environment, whether through climate change or destroying wildlife habitats. And it’s only right that we do take a greater concern for the stewardship of the Earth. However, to only see human activities through this negative filter is to miss out on the opportunities that science and technology offer to make life better.

Many of the ideas for new developments and technologies have their origin in human ingenuity – but if we were to discount what nature has on offer, we would be ignoring a vast source of possible new approaches and ideas. Human impact on the world is dramatic – yet what individual humans can do is still tiny in scale when compared with the forces and structures of nature. You only have to see the impact that a storm or an earthquake – or a virus – can have on our apparently well-planned lives to realise this.

In this book we will be investigating the way that nature can provide inspiration to our scientists and engineers – a process known as biomimetics. The term ‘biomimetic’ dates back to at least 1960 and literally means ‘emulating biology’ – ‘mimetic’ comes from ancient Latin and Greek terms meaning ‘being able to imitate’. This was a more general term than the roughly contemporary ‘bionic’, which is largely limited to electronic and mechanical imitation of the natural world.

The adjective was expanded to become a noun, ‘biomimetics’, by 1970 and would come to dominate, not only because it sounded more impressive than the dated-feeling ‘bionics’ but in conscious avoidance of association with the 1973 TV show, The Six Million Dollar Man about the bionic astronaut Steve Austin. The word ‘biomimetics’ is now sometimes used in a wider sense than focusing purely on the capabilities of biology, taking in technological advances where the original inspiration came from many different aspects of nature, and that is how it will be used here.

In making use of biomimetics, we recognise that the Earth is a vast laboratory where the mechanisms of natural selection have enabled evolutionary solutions to be developed for a wide range of problems. The difficulties that nature has evolved to cope with are often not the exact same ones that we face – but we can piggyback on the immense scope of natural experimentation and redeploy a solution to our advantage.

If anyone should doubt the capabilities of evolutionary solutions, consider the humble housefly. These small insects, typically 5 to 7 millimetres (0.2 to 0.3 inches) long, are common wherever humans live around the world. Next time you see a housefly, try and catch it in your hand. The chances are that it will easily avoid your grasp. Our technology is amazing. Yet we are very far from being able to build a robot the size of a housefly that can fly, walk and evade an attempt to catch it. Nature has evolved solutions to problems that remain well beyond our technological grasp.

All too often, the natural and the artificial are presented as opposing concepts, where everything natural is wonderful and the artificial is a poor second best, or even positively harmful. We should remember that ‘artificial’ means ‘made by human artifice’ – by skill. It’s not a bad thing. And raw nature can be a distinctly nasty place. Equally, though, it would be big-headed in the extreme to think that we are incapable of learning from the world around us. Not only is the laboratory of nature huge, it has been carrying out evolutionary experiments for billions of years. Most of these experiments end in failure – but there have been so many tried that enough have worked, and worked well, that we could spend many generations attempting to discover the transferable concepts derivable from nature.

To see how biomimetics can result in a simple yet highly practical solution to a problem, we will take a trip back in time to Switzerland in 1941. An electrical engineer named George de Mestral, at the time aged 34, was out hunting in Alpine woodland with his shotgun and his dog, Milka. As they headed for home, he noticed that his socks and coat, along with Milka’s fur, had picked up seed heads of the burdock plant, known as burrs.

The ability of these burrs to hitch a ride was the result of one of evolution’s many attempts to deal with a reproductive barrier faced by plants. Unlike animals, plants are static. By default, their seeds drop to the ground at the base of the plant. This is a problem because when the seeds germinate, they will be competing both with each other and the parent plant, attempting to access the same nutrients, sunlight and water. It would be far better for reproductive success if the young plants could put some space between themselves and their parent.

The way that evolution works is that traits that increase the chances that a species will successfully reproduce are more likely to be passed on to the next generation and so on. Plants that developed mutations that gave them a slight edge in dealing with this problem lived to pass these mutations on, making the traits increasingly dominant. This has happened in a multitude of ways to deal with the seed distribution problem. There are many plants, for example, that make use of the air to spread their seeds. This approach ranges from windblown seeds, such as the dandelion’s delicate ‘clock’ seed head to the helicopter-like wings found on some tree seeds, such as the sycamore, which enable the seeds to fly many metres from the tree.

Other plants have made use of the mobility of animals to give their seeds a lift. Many do this by giving the seeds a sweet coating, making the package attractive to eat. As a result, the seeds get passed through the animal’s digestive system to be deposited elsewhere. But there is an alternative approach. If a seed should happen to stick to an animal’s coat, it can piggyback on the moving animal, dropping off at a later time when it has been carried away from its parent. And it is this approach that came to be used by the burdock.

The heads of the plant, carrying seeds, are covered in little spines. At first sight these pointy extrusions may seem to be a way of putting off animals from eating the plant – but on closer inspection, these are not straight, pointed defensive spikes. Each spine ends in a small, tightly curved hook. When an animal brushes past, these hooks catch on the animal’s fur, pulling the seed head from the plant to later be deposited elsewhere.

For most people, these burrs might be interesting – or fun (I remember a game involving throwing them at people as a child, scoring points if the seed heads stuck) – but de Mestral saw a more interesting potential in them. What nature had developed was a way of getting two things to stick to each other without requiring stickiness. This meant that the adhesion would not deteriorate over time. Most sticky things lose their adhesive qualities if they are repeatedly stuck and removed. But unless the hooks get broken, a burr will continue to attach and re-attach itself to fibres indefinitely. At the same time, it’s an attachment that isn’t permanent. The seed heads are intended to come off the animal’s fur in time.

To de Mestral, this combination of an ability to repeatedly attach without losing grip, yet being relatively easy to remove when required, suggested a new way to make a fastener. Two pieces of a material, one featuring burr-like hooks, the other suitable fibres, would attach firmly to each other, but could be easily re-opened by simply pulling them apart. Getting from that first idea to a finished product took a considerable time. De Mestral obtained a first patent in 1955 and Velcro was launched on the world at the end of the 1950s.

From De Mestral’s patent for Velcro.

George de Mestral (1958), Separable Fastening Device, US3009235A, US Patent and Trademark Office

The original patent envisaged using two layers both lined with hooks: a ‘separable fastening device’, made up of ‘two layers of woven fabric of the velvet type in which the loops have been cut to form hooks’ – de Mestral had to invent a special device to do this cutting, based on barbers’ clippers. However, by the time of his updated 1958 patent, de Mestral noted that to work effectively, ‘the hooks of these layers of fabric are formed by a thread of artificial material, such as nylon’, with their shape preserved by heat treatment. ‘It has been found,’ says the patent ‘that the use of one layer of fabric of the hooked velvet type, as described above, with a layer of fabric of the loop type, such as terry or uncut velvet, provides greatly improved resistance to the separation of the two layers’.

De Mestral had improved on nature. The burrs attach to animal hairs. But a more secure attachment could be made if the hooks were paired with fabric covered in loops of fibre for the hooks to latch onto. The name de Mestral gave to his product was Velcro*, combining the French words for velvet (velours) and hook (crochet). This remains the registered trade name used by the company that developed the product, though other hook and loop fasteners now exist. Interestingly, in some languages, the invention is still directly linked to burdock in its name – in German, for example, it is Klettverschluss (burdock fastener) and in Norwegian borrelås (burdock lock).

Sometimes, a product inspired by nature has a very limited application – often similar to the way it was initially used. But these hook and loop fasteners have found uses far beyond the initial idea of a way of fastening together two fabrics as an alternative to a zipper. The fasteners occur on everything from trainers to cable ties, and from splints to aircraft. They have also been used in space, whether for keeping tools in place inside spacecraft or for nose-scratching sticks fixed inside astronauts’ helmets, leading to the frequently made, but entire false, assertion that Velcro was a spin-off benefit of the NASA space programme.

This, then, is biomimetics in action. A natural solution to a problem – how to be able to repeatedly fix two things together in a way that they can cleanly be separated – proved the inspiration for a product of human ingenuity. And the Velcro story fits perfectly with the narrative of biomimetics as a dramatic way of coming up with hugely successful new inventions that can help transform the world (even if it is in the less-than-Earth-shattering field of fasteners). Yet we will discover that the reality of biomimetics is often far more complex than this crude depiction – and what feel like transformative lessons from nature are often used once only, or never properly deployed at all. Understanding why this happens will be crucial to deciding whether biomimetics is a truly impressive concept, or an approach that is more show than substance.

Velcro was not the first invention to be inspired by nature, but before going deeper into the strengths and limitations of biomimetics, we need to take a step back and look at two key factors that come into play in the deployment of biomimetic solutions. The first is what evolution is and how it works – as this is primarily how the natural world develops solutions to problems in the first place. And the second is exactly what we mean by ‘technology’ and how it enables us to go beyond our evolutionary capabilities.

* The company descended from de Mestral’s original organisation want their product to be known as ‘VELCRO® Brand hook and loop fasteners’ rather than Velcro, as the term tends to be generically attached to a wider range of hook and loop fasteners. They have attempted to make ‘Don’t say Velcro’ go viral. When ‘Velcro’ is used in this text, please read ‘VELCRO® Brand hook and loop fasteners’. Confusingly, though, the strangely plural company is called ‘Velcro Companies’ not ‘VELCRO® Brand Companies’.

EVOLUTION AND TECHNOLOGY

2

Nature’s problem-solving technique

For a long time, biology was something of a Cinderella science. It lacked a big idea – it was, in physicist Ernest Rutherford’s cruel but accurate jibe about science other than physics, little more than ‘stamp collecting’. Rather than explaining how and why biological organisms had become the way they were, biology simply catalogued and described.

The theory of evolution changed this. Like all the most dramatic aspects of science it is an apparently simple concept that explains a whole range of outcomes. (That ‘apparently’ is important. Doing science almost always involves admitting that things are more complex than we first thought.) In fact, the basics of evolution are so simple and inevitable that it’s surprising it wasn’t thought up far earlier.

If we only take the fundamental core of evolution, all we are saying is that if organisms vary within a species, and that variation can be passed on to offspring, then the variants that are more likely to survive are more likely to pass on their characteristics to future generations. That’s it. Something that even the most fervent anti-evolution fanatic is likely to agree with.

Let’s take a ludicrously simplified example. Imagine there’s an environment in which heavy stones regularly rain down from the hills (it really doesn’t matter why this is happening – it could be volcanic activity, aggressive birds or aliens having fun). And we have a species living there in which some individuals have got a strong shell, but some have a much weaker shell. Then it’s pretty obvious that the organisms with the strong shells are more likely to survive long enough to have offspring. So, over time, more and more of the organisms will be of the hard-shelled variety.

Note that no intelligence is required in making this happen. There is no conscious design or intended direction of development. This was a random variation in the strength of the shells of the creatures.* And that, combined with passing on the characteristic of having a strong shell to the next generation, was enough to change the nature of the species to deal with the problem of falling stones.

This is how biological nature deals with difficulties. So, for example, in the previous chapter I mentioned that ‘other plants have made use of the mobility of animals to give their seeds a lift. Many do this by giving the seeds a sweet coating, making the package attractive to eat’ – it sounds as if the plants are consciously deciding to give their seeds a sweet coating. It is very difficult to describe the process without it sounding like it is designed with a goal in mind. Nothing could be further from the truth as far as evolution is concerned. It involves repeated random variations, some beneficial, some harmful. Over the generations, the variants that are better able to survive pass on their abilities – and gradually solutions emerge.

This is often a slow, messy process. Although there are variants that can change details of an organism over a small timescale – think, for instance, of the frequent emergence of new variants of the SARS-CoV-2 virus that caused the Covid-19 pandemic – large changes, particularly in complex organisms, can take thousands or millions of years. But life has been around on Earth for several billion years, giving plenty of opportunity to develop solutions to challenging problems.

One particularly important point to understand is that evolution is not an optimising process. Because it is not aiming for a solution, but rather is simply wandering around randomly and happening upon an approach, nature’s solutions are not necessarily the best way to do something. In fact, many biological structures and processes seem to work despite the way they are put together, based on what would be overly complex designs had they been designed. Nonetheless, given the vast scope of its laboratory in time, space and variation of environment, nature has managed to come up with many solutions to problems we could not hope to deal with using current technology.

The ‘T’ word

But what is ‘technology’? It’s what makes us distinctive as a species. Biologists tend to dismiss the concept of ‘human exceptionalism’ – the idea that humans are in some way special when compared with other organisms. Yet Homo sapiens has one huge distinction from other species in the way that we make use of technology to modify our abilities and the environment. This has arguably transformed the human being into a unique organism.

Some suggest this is still unwarranted exceptionalism, as other animals have been known to make use of tools. Chimpanzees, and a number of other apes, have been observed using rocks or twigs or leaves for a range of practical applications from missiles to a means of extracting tasty grubs from rotting logs. What’s more, this kind of ability is not limited to primates – notably in the form of the New Caledonian crow. This canny bird is another user of twigs to retrieve otherwise inaccessible insects and has been observed intentionally producing a hooked end on a tool to make it more effective in rooting out a juicy bug.

However, highlighting the use of tools by animals other than humans is highly misleading. Firstly, the vast majority of primate species never use tools – and the few cases where they do have typically been one-offs, rather than a consistent ability that is found across the species. Even close relatives of chimps (and ours) such as gorillas and bonobos show very limited evidence of tool use. And secondly, this tool use does not in any way compare with the human use of technology because it is not transformative. Apes and crows use tools to be a little better at performing an existing task. Humans have used technology to give them abilities they never previously had, and to change their environment to make it more suitable for human life. As climate change demonstrates, we aren’t necessarily very good at thinking through the long-term implications of those changes, but that doesn’t undermine the transformative nature of our innovations.

When we use tools and technology, we span a whole spectrum of possibilities from slightly more sophisticated solutions to problems than the approaches chosen by apes and crows to taking on tasks that would be otherwise entirely impossible. Take a very simple example. Some while ago I was walking part of the Ridgeway, a national trail in the UK, on a blazing hot summer’s day. Without the use of simple technology, this journey would have been sheer madness. It would just not have been safely possible. There was no water along the trail – the ground was bone dry. But I was able to keep going hour after hour because I carried water with me.

My water bottle achieved what nature took millions of years to develop in a camel – the ability to carry enough water to survive in an arid terrain. An unremarkable plastic bottle replaced a huge and complex biological transformation. This is already at least one step beyond, say, a chimpanzee using a leaf as a drinking vessel. The water bottle is something different in nature from the cupped hand that a leaf replaces because it could hold the water for as long as was required, while I walked, without taking up any of my attention.

Technology doesn’t have to be technological

When technology is mentioned, we tend to think of complex devices, often based on electronics – but technology like the water bottle began to transform our abilities long before electrons were conquered as tools in the 20th century. Electronics inevitably brings to mind information and communication technology but, equally, such technology was transformative long before digital devices came on the scene.

Think, for a moment, of the impact of writing, a technology that dates back at least 5,000 years and was dreamed up independently in many early civilisations. The transformative power of writing lies in the ability to expand person-to-person communication beyond the here and now. Communication is a common trait in animals and even some plant species* – but it operates locally and ephemerally. My bookshelves, by contrast, contain written words from a book published today (I’m writing this on the day my book Game Theory was launched) through science fiction classics from the 1950s to Jane Austen’s words from the early 19th century all the way back to works from over 2,000 years ago – whether we’re talking Aristotle and Archimedes or the Bible.

Writing arguably benefited two main activities essential to the development of modern humans: storytelling and record keeping. Telling stories is far more than entertainment. We are, at heart, storytelling animals. Some even suggest it is the most distinctive of human capabilities. A book like this one is just as much a narrative as Pride and Prejudice