Spider Goats

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In 2012, Japan’s Nara Medical University’s Shigeyoshi Osaki decided to make the worlds most beautiful sounding violin strings, and he did so with the help of 300 female Nephila maculata orb web spiders. Just as the fame of Stradivari’s violins is attributed to the dense spruce used to make the instrument, Osaki claims that the spider silk’s densely compacted fibers give them their unique and beautiful sound.

Spider silk has long been regarded as nature’s strongest material, having a tensile strength greater than Kevlar. It can be used to make artificial ligaments and tendons, airplane parts and protective clothing, and now — violin strings. For each string, Dr Osaki twists between 3,000 and 5,000 individual strands of silk in one direction, then twists three of these bundles together in the opposite direction. Because of the spider silk’s malleability, the perfectly round strands compress together in Dr Osaki’s string, leaving no space between each strand. This density, illustrated in electron microscope imaging of the strings’ cross-section, is what gives the string its beautiful, soft, profound sound. “Several professional violinists reported that spider strings… generated a preferable timbre, being able to create a new music,” he wrote. “The violin strings are a novel practical use for spider silk as a kind of high value-added product, and offer a distinctive type of timbre for both violin players and music lovers worldwide.”

A valuable commodity indeed — however, the difficulty of mass production is due not only to the fact that 15,000 silk strands are needed to make every string, but also because spiders are highly territorial and cannibalistic and therefore cannot be farmed. This is where molecular biologist Dr. Randy Lewis stepped in with a brilliant idea that manufactures spider silk while bypassing the need for having to harvest from the spiders themselves. From his own collection of orb spiders, Lewis took the DNA responsible for generating the silk protein and injected it into the embryo of a female goat, which was then planted into an acceptor female to grow a baby “spider-goat”. These goats grow up to produce spider silk liquid protein in their milk, which is taken to a lab and purified for removal. Scientists then mimic what the spiders do in making the fiber: they pull it through spinnerets and stretch it into long threads, which can then be used to create a variety of heavy-duty materials — such as the strings of an instrument, or even parts of a bridge, airplane, automobile, or suit of armor.

(In 2015, spider silk’s reputation as nature’s toughest material was dethroned after a study published in Journal of the Royal Society Interface proclaimed that the teeth of some species of limpets, a type of aquatic snail, are up to 40 percent stronger than the strongest spider silk. As strange and technologically innovative as this world is, I wouldn’t be surprised if limpet laboratory sweatshops start popping up and we begin to string our guitars with snail teeth.)

 

Did you find this article interesting? If so, read Sonic Spiderwebs, a recent AudioNitro article on how spiders tune their own webs like string instruments!

 

Photo by Narek75 (Own work) [CC BY-SA 4.0 (https://creativecommons.org/licenses/by-sa/4.0)]