Engineering from Evolution

Evolution has been continually occurring on Earth for around 3.8 billion years. In this time life has moved from a relatively simple unicellular organism to a fantastic interacting web of life with highly complex life systems and integrated cycles. Humans have been present for a tiny 0.004% of this time. In these billions of years, nature has managed to overcome almost every challenge imaginable, with chance mutations allowing novel ideas to constantly be tested and only allowing the most successful solutions to survive. Surely we should be looking to this wealth of design to find solutions to our own problems?

 

In 1997 ‘Biomimicry’ was published by Janine Benyus, creating an entirely new discipline. The book championed the idea of looking to nature to solve our problems, understanding how evolution bypassed problems and then applying them to human life. Benyus claims that not only will studying nature’s solutions speed up our own efforts but it will create more efficient more sustainable solutions. Since the book’s publication, the world of biomimicry, also known as biomimetics, has expanded with more and more products hitting the market inspired by natural design.

Shark Skin

Shark skin acts like a chain-mail against predators with a layer of v-shaped scale-like structures coated in enamel, called denticles, providing a robust defence. The structure of the denticles also allows the shark another crucial advantage – speed. Denticles cause the water streams to split as it is passed over them creating areas of low pressure, allowing additional thrust vital for fast pace hunting. Swimwear brand Speedo launched the LZR suit with inspiration from these dendrites and worn by Michael Phelps in the Beijing Olympic Games where multiple world records were set.

The denticles making up shark skin. Credit: Pascal Deynat/Odontobase
Sharklet material.  Credit: Sharklet technologies.

 

 

 

 

 

 

 

 

Another fascinating aspect of shark skin is it’s resistance to the attachment of pathogens and pests. The nanostructure gives such a small surface area that pests such as algae and barnacles cannot attach. This design has now been mimicked to prevent biofouling – the attachment of marine organisms to underwater equipment such as ship hulls and pipes, which costs the shipping industry around $1 billion a year due to the higher fuel costs from increased drag. Previously toxic paints have been used to prevent attachment, however, these are damaging to the environment. Using a silicon-based imitation of the dendrites on ship hulls has proven to give a 67% reduction in biofouling, showing the potential of the method to provide a sustainable solution.

Sharklet is another exciting material to emerge from the inspiration of shark skin. Emulating the structure has shown to reduce the spread of bacteria due to the inability of the bacteria to adhere to the rough surface. Tests found it reduced the contamination of bacteria by as much as 97%. This technology is vital when facing the threat of antibiotic resistance in bacteria, alternative methods must be found to combat bacteria, especially in hospitals, where MRSA remains a massive threat.

A Butterflies Wing

We are all familiar with the annoyance of using a screen in bright sunlight, but what if your screen became more visible in bright sunlight instead of a blinding glare? In 1984 a man called Mark Miles began looking at how insects, such as the Morpho butterflies produce such a brilliant blue colour on their wings. These butterflies do not use pigments like most organisms, rather they use structures called nano-scales to form structural pigment. Ridges on the wings interact with the different wavelengths of light in a novel way – some wavelengths are intensified, and others cancelled out in a process called constructive and destructive interference. In the Morpho butterfly, this allows for all wavelengths to be cancelled out except for the beautiful, vibrant blue reflected back.

A brilliant blue Morpho butterfly.

This structural colour is now being adapted to work in electronic screens in the form of Mirasol technology. Cells are made up of glass and a membrane which can move when exposed to an electric current, moving the membrane to different heights allows different wavelengths to be reflected and so different colours to be produced. Using a combination of cells in a single pixel allows any colour to be made and therefore any image can be produced. This technology holds the potential to revolutionise screens with a very low energy use and strong colours even in bright light. However, the technique has not quite been perfected yet with a long transition time between changing the pixel colours, but with rumours of Apple taking over the Mirasol lab perhaps this nature-inspired technology will be with us in the not-too-distant future.

Preying Mantis Robots

Picture an automated robot on an assembly line, with almost perfect accuracy it can pick up, manipulate and move the desired products.

The current technology is based on the 3D vision – stereopsis – of mammals and birds. Depth perception is critical for our daily life, just brushing your teeth without it would be a nightmare. One may assume that with increased complexity comes greater success, however, evolution does not always pave the most direct route. Mammalian and avian stereopsis works by comparing the amount of light in each image the eye produces, however praying mantis use a much simpler method. The insect’s eyes detect only changing levels of light from each eye’s image, this means that instead of constantly comparing the two images for differences they can simply detect the areas where there is active change – a vital system for catching moving prey when limited brainpower is available.

Applying this method to robotics would allow for a simpler system and far less computing power giving the flexibility to use this technology in simpler, and smaller, robotics. Furthermore, the technology is potentially more accurate – tests using humans and praying mantis’s found the insects to outperform our eyes in multiple depth perception challenges.

And the best part? Discovering the mechanics of praying mantis vision required the use of tiny praying mantis sized 3D glasses.

It is clear from these brief examples that there is so much to be learnt from studying nature, and even more examples can be found on asknature.org, the site set up by Janine Benyus. In the 21st Century, it may be easy to view nature as a force to be beaten, to be controlled. So far we’re having a pretty good stab at it, with dams, pesticides, domesticated wild species and even the ability to manipulate the weather. But when we start looking at nature as a force to be beaten we lose sight that is a strength to be respected, protected and to learn from.

 

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