Why Making Spider Silk Is So Tricky – Part 1
Why has the dream of making tons of spider silk been so elusive, and how are we finally turning that dream into a reality?
People have been captivated by the allure of silk for ages. The quest for spider silk has been particularly intense. The awesomeness of spider silk is a story in itself, but here it is in a nutshell: Spider silk is massively strong and phenomenally lightweight.
We’re not the first people to figure that out. We don’t even live in the same century as the first people who figured it out. Did you know that both Louis XIV and Napoleon are rumored to have had articles of clothing made from spider silk? (Not that we expect anything less from the King of Couture.) There have also been more recent attempts to harness the power of spider silk, including this golden fabric by Nicholas Godley and Simon Peers, which was made using silk from more than a million wild spiders.
Cape made from Madagascar Golden Orb spider silk
These garments relied on harvesting silk from actual spiders, which is… problematic. You can’t simply pop over to your favorite clothing retailer and buy garments made of spider silk, because farming spiders and harvesting their silk isn’t a day at the beach. At least, not any beach we’d want to visit. Spiders are cannibalistic, so you can’t raise them too close to each other. They’re territorial and they bite, so the employee turnover rate for spider shepherds would be pretty high. It’s also a matter of sheer volume – webs require far less silk than cocoons, so spiders just don’t make as much silk as silkworms do.
Okay, so no one is racing to become a spider farmer. Silk is a protein, and if you’re familiar with proteins, you might be wondering: why can’t we just synthesize the protein in a lab, the way some peptides are synthesized? Unfortunately, chemical synthesis isn’t sophisticated enough to make such a long protein. And it would be really expensive!
Even if you could synthesize silk protein, you’d still have to figure out how to spin the protein into fibers.
Spiders do it, so why can’t you just replicate the way a spider spins silk, sans the spider? Well, copying the spider isn’t as easy as it sounds. We don’t know exactly how the spider uses anatomical conditions (like geometry, pH, and other factors) to make fibers out of their liquid silk protein dope. Even if we could precisely copy spiders, they don’t spin silk quickly enough. To produce commercial quantities of silk, we can’t just copy the spider – we have to one-up it.
To learn how we’re on-upping the spider, stay tuned for our next post!