Looking to Nature for Engineering Inspiration!

By Becca Smithers

The natural world is full of incredible feats of engineering honed to near perfection through evolution by natural selection. Humans have the advantage of amazing technology and design so that we can manufacture our own versions of these biological marvels. This is a process called biomimicry.

Texture of shark skin reduces drag and infection. CC-0 Pixabay

Shark Skin

Shark skin is made up of overlapping scales called dermal denticles, which essentially means “skin teeth”. They have rough edges which help to stop drag caused by water swirling around the shark’s body. Drag is a force that can slow down the shark so these dermal denticles help the shark to move faster through the water.

Swimming costumes have been made to mimic shark skin and are now banned from sporting events as they can give swimmers an unfair advantage. Another benefit of the rough edged dermal denticles is that it is very difficult for bacteria to grow on the skin’s surface. Engineers are looking into making coatings for hospital surfaces that mimic shark skin to help reduce hospital infections.

Whale Fins

Whales have large, smooth fins that help to move the giant bodies of the whales through water. The shape of the fin allows water to move over it quickly helping to reduce drag in the water. Engineers have mimicked the shape of the whale fin and applied it to wind turbines. The shape minimises the effect of air resistance (drag) slowing down the turbine, so the blades can move smoothly through the air as the wind blows them round, helping to generate more electricity, Discover More here.

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Whale fins mimicked in wind turbines. CC-0 Pixabay.

Cat’s Eyes

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Reflective eyes help to see in the dark. CC-0 Pixabay

Cats and many other animals have a reflective layer in their eyes called the tapetum lucidium. Its role is to reflect light shining through the retina of the eye back through the retina again. This maximises the amount of light the eyes are receiving so makes images brighter but blurrier. This is an advantage at night when cats are hunting, they don’t need to see clearly but they do need to see in the dark!

Inventor Percy Shaw created the cat’s eye to be used on roads, mimicking the reflective quality of the tapetum lucidium. Cat’s eyes are small metal implants in the road with reflective surfaces to reflect the light of headlights of cars. They are used to show where roads divide and the edges of roads to help people drive more safely in the dark.

Tips of Eagle Wings

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Curved tips of eagle wings deflect drag. CC-0 Pixabay.

Aeronautical engineers at Air Bus Group have developed curved tips on the ends of aeroplane wings, mimicking the wing tips of eagles. Bird and aeroplane wings in flight have high air pressure under the wing to help give them lift, and low air pressure above the wing. At the edge of the wing these air pressures meet and mix, swirling and causing drag which can slow down the birds and the planes.

Eagle wings have curved tips to flick away this swirling mixture of air pressure so the drag happens away from the wing and the bird is not slowed down. Air Bus Group have mimicked this for their aeroplanes making them faster and also quieter.

Burr on Plants

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Burdock burr, the inspiration for Velcro. CC-0 Pixabay.

Burr is a structure on some plants designed to protect the seed from being eaten. The burr is a spiny case that surrounds the seed and is commonly snagged on fur of animals that help to spread around the seed and help it to grow more wildly.

The inventor of Velcro was inspired by burrs from the plant burdock. Electrical engineer George de Mestral noticed how these seed packets clung to his dog’s fur. He mimicked the design of the spiny hooks of the plant on one piece of fabric, and the fur of his dog on a fluffy piece of fabric, and Velcro was born.

Mosquito Proboscis

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Mosquito bites are painless due to proboscis shape. CC-0 Pixabay.

The proboscis of a mosquito is the part of the mosquito that pierces the skin and drinks the blood of humans and other animals. Mosquitoes can take blood from their prey without the animal noticing, it is quite often a painless process. Mosquitoes are incredibly dangerous to humans in areas where malaria is common, but we can learn from the mosquito’s proboscis.

Medical engineers in Japan, led by Seiji Aoyagi, have designed a needle that makes injections less painful. Aoyagi noticed that the mosquito proboscis has serrated edges so there are small points of contact with the skin, whereas injection needles are smooth so there is a lot more metal in contact with the skin and pain receptors. Ayoagi and his team are still working on this needle as it is more brittle than normal injection needles, but they are making brilliant progress.

Kingfisher Bills

The kingfisher is a bird that lives in river banks, quickly zooming up the river in the air and diving into the river to hunt for food. When its beak comes in contact with the water it doesn’t make a splash which allows the kingfisher to see its prey and doesn’t give the prey much warning.

Engineers working on the Shinkansen Bullet Train in Japan looked to the kingfisher when they needed to address a problem with its design. The bullet train can travel up to 200 mph but the sound it made, especially when going through a tunnel, caused a boom that exceeded environmental sound standards. The engineers redesigned the front of the train to have a smooth bill shaped tip like the kingfisher and the result was that the train could go 10% faster than before and even used 15% less electricity. The engineer who made the connection was Eiji Nakatsu, who is a bird watcher in his spare time.

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Mimicking kingfisher bills made the Shinkansen Bullet Train more efficient. CC-0 Pixabay.

Bat Echolocation

Bats use echolocation to navigate and hunt. CC-BY Angell Williams

Bats use echolocation to navigate and hunt. CC-BY Angell Williams

Bats fly around at night to catch their prey and they use echolocation to do so. They emit an ultrasonic sound, which means it is too high for humans to hear, which bounces off their surroundings and back to the bat so it can build up a picture of where it is. This echolocation is so precise that bats can pick tiny insects out of the air and fly through dense woodland without hitting any trees.

Engineers have mimicked echolocation to develop SONAR (Sound Navigation and Ranging) used in military operations to locate objects, and also in drilling under seas to ensure the path is clear for the drill. It is often used underwater and can be used for navigation and communication in submarines.


 

These are just a few examples of the amazing technology produced by engineers who are looking to nature for answers. If you would like to find out more click here or watch this brilliant TED Talk by Janine Benyus for more examples of biomimicry!

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Posted in Biology, Engineering