Taking technology cues from nature
From viruses to the human brain, the interaction between nature and engineering provides solutions and greater understanding of how the world works, writes Alan Finkel.
The deadly AIDS virus is a master of exploitation. Using receptors on our cells like door handles, it gains entry, multiplies using our DNA, and then sends off its progeny to infect more cells using the cell’s export system. But some individuals are able to foil the virus. Either minor differences in their DNA code mean the virus can’t exploit their cellular workings or their immune systems are more adept at searching and destroying infected cells. So even if we did not have medicines to treat the virus, the human species would still survive, just as it has survived countless other viral campaigns through the eons. In other words, species survive deadly viruses through biodiversity.
Like their biological namesakes, computer viruses also exploit their hosts' machinery. They insert themselves into the code of computer programs and force them to do wicked things they were never intended to do.
Taking a cue from nature, it has recently been proposed that every newly installed copy of software, such as Microsoft Outlook or Apple’s OSX operating system, should be engineered to be internally unique. This would be a huge break from traditional manufacturing in which the code in a particular version of the software is identical to every other copy. In the proposed scenario, each copy’s internal code would be subtly different. However, the way the programs communicate with disks, screens, keyboards and the internet would be preserved and identical.
The advantage of this proposal is that because internally each copy of the code would be slightly different to every other copy, malignant viruses would not know how to insert themselves into the code sequence without breaking the program and therefore their own prospects of spreading and doing harm. If this new practice were widely adopted, it might be the ultimate defence against computer viruses, or at the very least it would set the malicious hackers back a giant step. Chalk one up for nature.
Sometimes we fail to take the cue from nature because its strategy is so sophisticated we cannot understand it until we have independently invented the same thing. A stunning example is our understanding of how the cochlear in our ear works.
Although not every clever trick in nature is applicable
to the world of technology, there are some terrific examples.
In 1807, long before the era of cellular neuroscience, a French genius named Joseph Fourier developed a mathematical theory that every complex repeating wave found in nature, such as the trill of a canary or the high C of an opera singer, can be broken down into its pure components or “sine waves”. This technique is known as transforming the signal into the frequency spectrum.
Much later, in the 1940s, the Hungarian scientist Georg von Békésy studied the cochlear in the inner ear of human cadavers. He found that the tubular, coiled bone was filled with liquid and lined with cells that sprout bundles of tiny hairs. The hairs vibrate in response to individual sine waves in the sound wave, with the hair cells at one end responding to the lowest frequencies and the hair cells at the other end responding to the highest frequencies. In short, the cochlear actually picks apart complex sound into its component sine waves. In engineering terms the cochlear is a mechanical “spectrum analyser”. It biologically achieves exactly what Fourier developed mathematically in 1807, and Fourier’s theory is now widely used in the construction of electronic keyboards and cinema sound systems. Nature has been transforming sound into a spectrum of frequencies since ears first evolved; but we needed to invent the same technique before we could appreciate nature’s achievement.
Not every attempt to learn from nature works. Take bird flight. Inventors have tried to make flapping-wing aircraft with little success. Ornithopters, as they are called, featured in Frank Herbert’s 1965 book Dune – but the reality is that flapping wings are not as efficient for large, high-speed aircraft as fixed wings with propeller or jet engines.
Similarly, none of nature’s creatures use wheels to travel despite them being wonderfully efficient and the dominant means of mechanical transport. An obvious reason why wheels never evolved for creature transport is the difficulty of connecting the blood supply to continuously rotating appendages.
Although not every clever trick in nature is applicable to the world of technology, there are some terrific examples. For instance, there are growing successes developing “neuromorphic” computers that use silicon to mimic the computing logic of the human brain, helping computers at Google and Facebook perform hitherto intractable tasks such as recognising human faces. And in the world of 3D printing, researchers are developing materials that mimic the structure of bone to provide great strength at low mass.
It’s a circular activity – the more we understand, the clearer we see; the clearer we see, the more we understand. The interaction between nature and engineering is a marvel to behold.