Natures Nylon

"What Skill is the frame of Insects shown? How fine the Threads, in their small Textures spun?"        -Richard Leigh, 'Greatness in Little'

    Arachnophobia is the fear of spiders. Spiders haunt the mind of many people for many reasons. Maybe it is the eight eyes that scare people, or maybe it is the fear of the poison that spiders may have. In reality, there are only a few large, hairy poisonous spiders. Chapter 3 of The Gecko's Foot talks about the complexity of spider silk and how it could potentially be a good resource and the difficulty of producing this silk.
    The resilience of spider silk has long suggested the application of humans basically because it is so strong that it can capture an insect at speed without breaking. We sometimes think that spider silk is a delicate structure, which they are by themselves, but when combined together they can create a very strong material. For example, in Papua New Guinea, they have been draped across bamboo poles to make fishing nets. But producing a massive amount of spider silk to produce these kinds of materials is very difficult.
    The first spider silk exploit documented was in 1709 by a Frenchman named Xavier Saint-Hilaire Bon. He made gloves and stockings from the silk and presented them to King Louis XIV. In 1879 the Chinese Emperor made a gown made of entirely spider silk for Queen Victoria, and in the late 18th century, Austria had a tradition of painting on spider webs. There isn't a problem with spinning silk from a single spider but the problem is producing enough silk to make a useful product. It is estimated that you would need 27,468 female garden spiders to make 1 lb of spider silk. It is also nearly impossible to farm spiders because they are aggressive, solitary animals. This turned into the idea of creating a synthetic silk.
    In 1891, rayon (a silk like substance) was produced from cellulose, but the mimicking of natural silk on a commercial scale started with nylon in 1937. The structure of nylon is very different to the structure of natural silk but they have one thing in common and that is the amide group. The first serious product produced from nylon was Kevlar in 1963. But nylon and Kevlar are made with toxic chemicals and generate toxic waste. They are not biodegradable. With this situation, Nexia Biotechnologies in Quebec, Canada, claimed that they were able to produce an industrial amount of spider silk from genetically modified milk of goats. This silk was called BioSteel and it was developed under an Army contract to make flak jackets. BioSteel was very strong and useful for the Army. Nexia could not meet the Army's requirements for quality or quantity so the US Army withdrew from the industry. BioSteel has since then been downgraded because of its technical difficulties of producing bulk amounts. Below is a picture of nylon and Kevlar.
                                                                            Nylon

Kevlar

 

    The next approach to make a synthetic spider silk comes from David Knight. He founded Spinox, a company dedicated to producing technical silks. David focuses more on the spinneret on the spider to make the silk. A spiders spinneret produces a solid filament from the fluid silk inside of the spider. David made a spinner that can spin the liquid silk into a solid product. David's spinneret never made it to the industrial stage. In an interview with Knight and Forbes, Knight states that when spider silk is finally commercially produced, it wouldn't first go to the army first, but it would be used for biomedical applications such as fibers for closing wounds and other medical aids.
    The quest of producing a synthetic spider silk is ever going. It is proving to be a difficult process. This just shows the complexity of nature and how hard it is to mimic it's great creations. With bio-inspiration, it is becoming much easier to achieve.