Stronger than steel and stretchier than elastic, synthetic silk could transform clothing

US startup Bolt Threads reckons it has one-upped spiders to unlock the incredible potential of synthetic silk.

Richard Trenholm Former Movie and TV Senior Editor
Richard Trenholm was CNET's film and TV editor, covering the big screen, small screen and streaming. A member of the Film Critic's Circle, he's covered technology and culture from London's tech scene to Europe's refugee camps to the Sundance film festival.
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Richard Trenholm
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A US startup wants to disrupt spiders with synthetic silk.


DUBLIN -- If Bolt Threads has its way, the clothes of the future could be made from synthetic fibres similar to the web fired from Spider-Man's wrists. How's that for wearable technology?

Imagine for a moment that someone from the 1950s time-travelled to today. They would no doubt be astounded by many of our modern technological marvels, but they could take comfort at how familiar they'd find one important aspect of human culture: our clothes. Skirts might be shorter and T-shirts more colourful, but we've been wearing largely the same fabrics for many years now, such as cotton, wool and silk.

That's where Bolt Threads comes in.

Bolt Threads is a California-based startup that claims to have cracked the much-sought-after trick to synthesising artificial silk. Silk is an incredibly versatile substance, with the potential to be many times stronger than steel and stretchier than rubber, among its many properties -- spiders can naturally produce different kinds of silk for different purposes.

The company is among several groups trying to emulate the properties of spider silk to create a synthetic material useful for various purposes. Previous efforts by other groups have included the 3D printing of fabric from a liquid sprayed onto molds and making mutant superspiders that produce fibers stronger than they'd naturally be. So far the results have largely been prohibitively expensive, difficult to scale to mass production, or both.

The problem with naturally getting silk from spiders and silk worms is that they're not the most cooperative workforce. It's hard to farm spiders, for example, because they have a tendency to eat each other.

The folks at Bolt reckon they have cracked those problems, and we'll see the fruits of their looms soon. Backed by government grants from their academic roots and with venture capital money, the company plans to launch synthetic Bolt fabrics as a brand used by other clothing companies to make their clothes -- similar to the way Gore-Tex labels, for instance, appear on clothes from different fashion brands.

I interviewed Bolt co-founder Dan Widmaier Thursday on the fashion stage at the annual Web Summit conference in Dublin, where he promised that the early partnerships would be with well-known brands. He said that though early Bolt clothing would cost a premium, the company plans to keep prices affordable for consumers.

Bolt creates its fabric using yeast to create silk protein, minutely adjusting the ingredients and the process to shape the properties of the finished product. The company controls the whole production process, right down to buying the corn that produces the yeast. According to Widmaier, the reason Bolt has apparently cracked the secret of success where many others have tried is that general advances in biology mean they're in the right place at the right time.

Widmaier also claims that the environmental impact of synthetic fabric will be exponentially less than current textile production. The actual impact won't be clear until production scales up, however.

It remains to be seen if Bolt can scale as a business, but the potential advantages of the company's synthetic fabrics sound pretty impressive. By fine-tuning the process of synthesising the fabric, Bolt says, it can control the textile's properties. So Bolt can make a lighter fabric for warm-weather clothing, a stronger fabric for hard-wearing clothes as well as make the clothes easy to wash and maintain. It can make waterproof fabric for outdoor clothing, and "where it gets interesting," according to Widmaier, "is when we start combining those properties."

Bolt chose to enter apparel initially because the market is established, with a proven need for the product. It also helps that Widmaier is married to a fashion designer. But beyond fashion, synthetic fabric could be used to make all sorts of other products. With increased strength in lighter material it could be used to make a lightweight bulletproof vest, for example. It could be used for medical devices or even composite materials for aircraft and construction.

Yes, yes, but I know what you're thinking: what about Spider-Man's web-shooters? Widmaier gets asked all the time about the Marvel superhero and his skill for firing spider-ropes from his wrist to swing between buildings, but Widmaier acknowledges that it's an easy way to explain Bolt's product. And he says the company can produce exactly the sort of high-strength filaments Spider-Man shoots, but the problem is firing them.

"That's a mechanical problem," Widmaier said, laughing.