We were promised carbon-nanotube space elevators, nanorobots that would mend us from the inside out, bulletproof vests made from spider silk, and so much more. What we will get, at least when it comes to arachnid materials, is a $314.15, limited edition spider-silk necktie.
Bolt Threads will unveil the tie, which the company calls the first commercially available spider-silk product, Friday at the South by Southwest conference in Austin, Texas. David Breslauer, chief scientific officer at Bolt, says the production of the ties shows that spider silk fibers and textiles can be produced at large scale.
But don’t expect to see spider-silk ties in Bloomingdale’s anytime soon. Starting on Saturday, just 50 ties will be available on the company’s website. Breslauer says the tie is a showpiece and that Bolt will release a more widely available product soon, though he declined to provide any details.
Spider silk’s properties have excited biomaterials researchers and the public for some time. The structure of spider-silk proteins, which mixes hard, crystalline regions with more elastic ones, gives the material some superlative properties. When single strands of spider silk are tested in the lab, the best can hold their own against steel and Kevlar, the material used to make bulletproof vests. Silks are versatile, and different spider species have their own distinct variations on the silk formula.
A handful of startups are now trying to replicate that silk production in the lab. Like Bolt, many of these companies draw on the genetic sequences of natural silk proteins, and grow them in microbial fermenters, then spin them into protein fibers. (For a look at Bolt’s process, see “Spinning Synthetic Spider Silk.”)
There have been false starts. Last May, Yamagata-based Spiber, Inc. announced, to much fanfare, that North Face would begin selling a $1,000 spider-silk parka in Japan. But by late September, Spiber announced that it had postponed the product launch “to further improve our production process for more stability of material quality.” Reached over e-mail, a Spiber representative said the company is continuing to learn about the fabrication process, and that it could not comment on the timing of any product releases.
Fiorenzo Omenetto, a silk researcher at Tufts University, says Bolt’s necktie is significant as a “tangible demonstration of manufacturing objects with a natural material that is synthesized in the lab.” It’s a sign of what’s to come in biomanufacturing, for textiles and beyond, he says.
Bolt’s Breslauer says his assumptions about what synthetic spider silk might be useful for have changed over time. “The allure of spider silk made me assume we’re going to make some technical material,” like fibers for bulletproof vests, he says. The silk in Bolt’s tie, he says, is not a super fiber, which is inherently more difficult to manufacture.
Indeed, synthetic spider silk seems to be going through its own version of the hype-to-reality-check trajectory experienced by many new materials. An exciting discovery in the lab is followed by wild speculation about everything it might enable, and then more research into the details and market realities yields something different.
That doesn’t mean that spidey stuff is not useful. Once Bolt is producing on larger scales, Breslauer says, it will start using silk protein variations that can more readily absorb dye, which would require much less water to process. And it should be possible to make biodegradable silk apparel—medical implants made of silk take advantage of this property, and clothing could, too.