As humans seek ever more urgently for ways to go faster, operate more efficiently, and work with greater resourcefulness, we are slowly coming to realise that many of the problems we are grappling with have already been solved.
Nature has billions of years of research and development invested in her designs, so it seems only logical that we (Homo sapiens), with a mere 200 000 years of knowledge and skill to our name, should look to her for direction. The discipline of biomimicry (from Greek bios, meaning life, and mimesis, meaning imitation) seeks to create solutions to human challenges by emulating ideas and designs found in the natural world. I have chosen only two rather disparate examples to share here − my choice inspired by the fact that these are not futuristic possibilities, but working examples of how nature has ‘created a genius to do a job’ and given us a blueprint to follow.
Speed, the essence of the modern age, is embodied in Japan’s Shinkansen trains which whisk their passengers from one place to another at 322km/h. Along the track, however, there are numerous tunnels which cause the air in front of the engine to be compressed when a train passes through at high speed. On leaving the tunnel, this air rushes outward, creating a window-rattling sonic boom. In a country with strict noise-pollution laws, something clearly had to be done about this.
Where to start looking? At a Kingfisher’s bill, of course! These small, beautifully-hued birds – many of which, although not all, eat fish – have a bill which is ideally shaped for a smooth, streamlined transition from air into water. The dramatic change in pressure experienced between the two mediums when the Kingfisher dives for its prey is similar to the change a high-speed train experiences when emerging from a tunnel into the open air. Large-scale wind-tunnel tests, and analysis by state-of-the-art computers, led to the conclusion that a shape almost identical to that of a Kingfisher’s bill would ameliorate this. Moreover, the design resulted in a 15% improvement in overall energy efficiency, a 10% increase in speed, and a more comfortable ride, all due to smaller changes in pressure when the train entered a tunnel.
Although a Great White Shark (Carcharodon carcharias) is not something you will encounter on safari – unless, of course, diving is on the agenda − these denizens of the deep are perfectly adapted to their environment. They are renowned for their stealth, and studies of their skin have shown that it is covered with tiny V-shaped scales, called dermal denticles, which are more like teeth than fish scales. These denticles decrease drag and turbulence, allowing the shark to swim faster and more quietly.
Scientists working with this 11 million-year-old prototype have been able to replicate dermal denticles for use in swimsuits, on the bottom of ships, and in wind turbines, to decrease drag and increase efficiency. Moreover, while many marine animals are known to host other species on their bodies (such as barnacles), sharks remain comparatively ‘clean’. It seems that these microscopic dermal denticles also help sharks fend-off micro-organisms. Anthony Brennan, a materials scientist at the University of Florida in Gainesville, saw the potential of a sharkskin-inspired coating being applied to the hulls of ships to prevent algal growth. Having previously had no success with many other designs, he tried the sharkskin model − and his test plates came back 85% clear of algae! A subsequent (and apparently totally unexpected) benefit of sharkskin-like surfaces is that they collect and hold 94% fewer bacteria than do smooth surfaces – outperforming even copper, a widely used germ-fighter. Additionally, because the surface works without killing microbes, there is no selection for resistance – thus limiting the development of ‘superbugs’.
Innovations continue. Spider-silk derivatives could be the future of directional microphone technology in hearing aids. Shock-absorbing compounds mimicking the fourfold arrangement used by woodpeckers to protect them from the 1200 Gs they experience 22 times a second while they drum on a tree, may help to improve the protection of flight-recorders. The list is infinite; nature’s patterns are “…endless forms most beautiful…” (Charles Darwin).
By Lorraine Doyle