Monday, 25 March 2013

So what is Biomimicry?



Sounds all sciency and intellectual doesn’t it? But it’s been done for hundreds of years.  Leonardo De Vinci designed a plane after studying the way birds fly in 1505, nearly 400 years before the first glider took to the skies.
The actual term comes from the Greek words “bios” meaning life, and “mimesis” meaning to imitate. So we look at life and nature around us and try to copy the best bits.

Animals, plants and insects in nature have evolved over billions of years to develop more efficient solutions, such as superhydrophobicity, self cleaning, self repair, energy conservation, drag reduction, dry adhesion, adaptive growth and so on, than comparable man-made solutions to date. Many people have solved problems by studying to understand the way nature copes with it. From swim suits and aircraft fuselage copying the way shark skin is formed and so helping improve efficiency and speed, to looking at the way termites keep their towering nests ventilated and copying this in high rise buildings to give them super-efficient ventilations systems that claim to use a 10th of the energy required to control a similar sized conventional building. There are many examples of problems that have been solved by studying the way nature deals with it.

In the field of textiles we see developments coming through all the time – 

·         The lotus effect refers to the very high water repellence (superhydrophobicity) exhibited by the leaves of the lotus flower. Dirt particles are picked up by water droplets due to a complex micro- and nanoscopic architecture of the surface, which minimizes adhesion. Some technologists have developed treatments and coatings for fabrics and other surfaces that can stay dry and clean themselves in the same way as the lotus leaf.
·         Velcro – arguably the best known of all. According to the story, George de Mestral, the Swiss inventor went for a walk in the fields with his dog. When he return, he noticed burrs stuck to his dog's fur. Upon closer inspection of the burrs, de Mestral discovered their hook-like construction, which led to his invention of the hook and loop fastener, Velcro

·         The pine cone effect- This is another example where biomimicry has been used to bring something new to the market. Working on the principle of a pine cone where it opens when in dry conditions and closes when in wet this has been applied to fibres to aid the moisture management in fabrics where there are changes in their micro-climate and therefore improving comfort for the user.



·         Shark skin – Humans are not efficient swimmers, for their shapes are not well suited to rapid travel through water. Swimming style is vital to a swimmer's speed, but beyond that, it is important to lower the skin friction drag experienced by swimmers. The movement of sharks in water, and in particular, the structure of their skin, has been of interest. The skin of most types of sharks is covered by tiny hard tooth-like three-dimensional scales, also called dermal denticles. The denticles have very fine and equi-spaced ridges and are aligned along the body axis. These tiny riblets of denticles vary in terms of number, size and shape depending on the sharks’ age and species. This lead to the ultimate focus of research studies in finding a way to imitate the surface of shark skin. Probably, the most well-known application of riblet surface morphology is in Fastskin swimwear technology (Speedo, Inc.). It was reportedly claimed that a 7.5 per cent reduction in drag would be experienced by the swimmer as a result of wearing the suit

And so the list could go on. Nature provides us with a huge amount of techniques to build with fibres to achieve specific goals, and there is tremendous potential to learn from it. Understanding the structure and function relationships is key in developing textile products that are, for example, adaptive, thermo-resistant, superhydrophobic, or self-healing, examples of which are plentiful in nature. The obvious need for sustainability requires not just mimicking natural design but also mimicking the process.

2 comments:

  1. In the course of my biomimicry research, one particular application struck me as rather fascinating: Jeffrey Karp’s replication of parasites to be used in various skin graft technologies. Though many of his early attempts to develop improved grafts for burn victims were unsuccessful, Karp et al. eventually drew inspiration from the manner in which Pomphorhynchus Iavis, parasitic entities often found in the guts of fish, attach and assimilate into their host. Explaining the process, Karp states “The tip of its proboscis swells once inside its host’s flesh, anchoring the worm to the guts.”
    With his team, Karp developed a textile very similar to the parasite — a sheet layered with micro needles which swell when wet. With this new technology, scientists and medical professionals believe we can now minimize the risks of past skin grafts such as water pooling and infection. By comparison, researcher Bohdan Pomahac states that “Staples or sutures provide only one point of contact, while micro needles can secure an entire area in multiple points.” Moreover, this extraordinary product of biomimicry boasts another lovely feature in it’s extremely low cost. With the initial molds costing $1000 and the individual sheets being produced for between $0.50 and $5, Karp and crew are looking into further applications for this modern marvel.

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    1. Thank you Lauren for your contribution. This is very interesting and certainly worthy of further investigation.

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