What new Americas of light have been
Yet undiscovered there, or yet unseen,
Art’s near approaches awfully forbid,
As in the majesty of nature hid.
RICHARD LEIGH, ‘Greatness in Little ’
Bio-inspiration represents an attitude to life that will be expressed in many different ways beyond the merely practical. It suggests a light aesthetic – in every sense, not just visual. You can find this sense of lightness in Lucretius, who has been a constant touchstone throughout the book, and the spirit of Lucretius was memorably evoked by Italo Calvino in Six Memos for the Next Millennium:
The De Rerum Natura of Lucretius is the first great work of poetry in which knowledge of the world tends to dissolve the solidity of the world, leading to a perception of all that is infinitely minute, light and mobile.
‘Infinitely minute, light and mobile’ would describe many of the subjects of this book. The larger structures described in the preceding two chapters cannot be infinitely minute but they are certainly light and some of them are mobile. Heaviness, both literally and spiritually, is the enemy. It is early days for bio-inspiration but there are signs that aesthetically it will be welcomed. For there is a turning away from the old, the heavy, the steeped-in-history. The new signature buildings of architects such as Santiago Calatrava and Frank Gehry are popular, as the antiques trade begins to struggle. In the search for this new lighter aesthetic, people are finally casting off the last remnants of Victorian clutter – the love of Gothic gloom and bric-a-brac. People are discovering the joy of living in their own time.
Nature and technology have been seen as polar opposites by many, with nature as a comforting balm for gritty hard-edged city technology. But nature at the nanolevel looks like…well, contemporary high technology and architecture! So the nature/technology antithesis breaks down in the face of the new science and technology. This is surely a good omen for the future. It signals a culture less divided, less neurotic about the natural and the synthetic, less timid and backward looking.
Bio-inspiration can contribute to a new aesthetic for our times in two ways. Firstly, in uncovering the mechanisms of some of nature’s most impressive and beautiful phenomena, it has greatly enlarged the scope of biology. The old, unhelpful divisions between molecular biology and the natural-history tradition, including fieldwork and the classification of species, is breaking down. Biology is becoming a complete and unified science. And to reiterate the essential thesis of Richard Dawkins’s book Unweaving the Rainbow: to understand the mechanisms of nature does not detract from the poetry. In bio-inspiration, not only does the science not detract from the poetry of nature, the science has uncovered hidden poetry. For millions of years the optical structures in the sea mouse and Morpho butterflies bent light in ways unknown to humanity. Bio-inspiration has opened up a new realm of nature as surely as did the coming of the microscope or the unravelling of the structure of DNA in 1953.
The second contribution lies in the potential applications of this work. Now we are on more difficult territory. Hubris is a common human weakness. No sooner have we begun, tentatively, to understand some natural mechanism than claims are made for instant technical nirvana. Almost every article written about bio-inspiration in the last few years has ended with a sentence to the effect that: ‘Soon we shall all be doing it the gecko’s/spider’s/butterfly’s way.’ I confess that some of them had my name on the byline. In the modern journalistic climate, it seems to be necessary to make this kind of pitch to win attention. And hype also unlocks research funding. As the work in this book has shown, the reality has been very different, with many setbacks and slower progress than anticipated.
This is no different to any other cutting-edge science. In the early 1980s, when genetic engineering became a reality, we were promised gene therapy within a few years. Some disastrous attempts were made within that time but, 20 years on, it all appears to be vastly more complicated than it seemed at first. During the timespan of writing this book, the fate of the individual projects waxed and waned unpredictably. Spider silk, which was trumpeted in the mainstream press as a success story about to deliver, received heavy setbacks, whereas photonic crystals, the revolutionary way of guiding light for computer optics, invented in 1987 and discovered to exist in many natural creatures, began to glow with promise. This process will go on. George de Mestral had to wait a decade or so for commercial nylon to enable him to produce his hook-and-loop fasteners but technologies can suffer even worse delays: the computer, effectively invented by Babbage in the 1830s, was still-born for over a century for lack of the science of electronics. Some of bio-inspiration’s ideas will similarly have to await their enabling technology. Having said all that, the range of techniques available now is so rich that a researcher stymied in one direction has plenty more to call on. But what we have yet to see emerge are standard generic techniques such as those used in silicon-chip manufacture.
Of the two kinds of bio-inspirationists, the materials scientists tend to be bullish because their science is a new frontier, just as molecular biology was in the 1960s. Biomechanics is an older discipline and its practitioners are more wary. As usual, I would guess that the true position lies somewhere between these poles. Applications there will certainly be but, except in a few cases, the gestation will be long – typically up to 20 years – and fraught with setbacks. That we have learnt so much about this nanorealm of nature does not mean that we shall soon know it all. D’Arcy Thompson, who made nature’s engineering his life’s work, at a time when clear answers were very hard to come by, said:
That nature keeps some of her secrets longer than others – that she tells the secret of the rainbow and hides that of the northern lights – is a lesson taught me when I was a boy.
There is a pattern in several of the stories, of an initial breakthrough leading to premature optimism. Nature’s mechanisms are subtle and complex but sometimes a crude approximation gives surprisingly good results – then the going starts to get tough. Spider silk and mussel glue are two such cases in point. Professor Bob Full insists that a slavish copying of nature will fail: you can only start to do something similar to nature’s work when you understand the underlying principle. And then what you make might be very different to the natural version. In the case of spider silk, you could argue that we had already abstracted the principle of spider silk when we made nylon – we can get by without the extra properties conjured by the spider. Nevertheless, getting to the bottom of these mechanisms must be as valid a piece of research as investigating black holes or pursuing the superstring theory of matter.
Much research will never lead to any technical product, but it is surprising how much of what once seemed innocuous, arcane and – to many people – rather pointless biological research does now have the prospect of potential commercial development. Early 20th-century papers on the gecko’s foot or structural colour in butterflies did not look as if they would ever be of interest to technologists.
Human technology has a long history and a very broad range of techniques: bio-inspiration is about 15 years old, although it has deeper roots in Germany, perhaps going back to the 1960s. Not the least of its virtues is that it gives an enormous boost to arguments in favour of conservation and biodiversity. The argument for biodiversity – apart from maintaining the general health of the planet and providing for human recreation – has always focused on the potential drugs that could exist in as yet unknown species and on the need to preserve the gene bank of economic crops.
But now, creatures that were formerly thought to be merely cute or weird, and to be preserved just for their oddity, turn out to be blueprints for entire new technologies. Geckos, spiders and flies formerly had no use at all or were regarded as pests. If geckos had been rendered extinct before the era of the electron microscope, it is unlikely that the adhesive mechanism they employ would ever have been discovered. And there could be species out there, harbouring nanosecrets, that are disappearing as I write. The more pointless bits of creation (from our point of view) just got more pointed.
Scientists don’t always speak with one voice, especially in an emerging multi-disciplinary subject. Time and again, talking to the scientists, disagreement was not far beneath the surface. In many cases, the right way to do these things has not yet emerged and the scientists are all too human in their need to defend their own patch and cast a surly eye on others who do things differently. Without putting names to phrases, ‘That’s nonsense!’ ‘That’s not data!’ ‘But that would be chemistry!’ ‘He doesn’t know anything about it!’ were a few of the noises off. Those who want science to be cut and dried will probably be disgusted by this but cantankerousness is all part of the passionate search for truth. And once definitive results are obtained, all will accept the result and some will admit they were wrong.
In this book, I have written about science and technology on the hoof because this is a new science and success is a matter of decades of work. Rather than wait until some of these technologies have become commonplace, I have tried to capture the Wordsworthian ‘bliss-it-was-in-that-dawn-to-be-alive’ moment of seeing what was, until 15 years ago, a wholly unexpected science take shape before our eyes.
Across the wide range of techniques covered in this book there is one overriding message: shape, shape, shape. At every size, from atoms to cabledomes, we see that shapes can do things we could hardly have expected. There are some who think that the three classical dimensions are boring: mathematicians play with geometries of any number of dimensions and at the further reaches of physics three dimensions no longer cut it.
But whether it is in surprising ways to get from folded to flat (Miura-ori), how to be self-cleaning (Lotus-Effect), how to stick without being sticky (the gecko’s foot), how to bend light to our purpose (photonic crystals), how to self-assemble electronic components (the molecular erector), how to raise a roof with tensile wires that ought to sag rather than soar (tensegrity) – in all of these it is the patterns these structures make in space rather than what they are made from that creates the effect. Galileo’s intuition, from the birth of modern science in the 17th century, that the book of nature is written in circles and squares and triangles, has been vindicated, although some of the shapes are far more complicated than he could ever have foreseen.