Your Future Clothes

How Artificial Spider Silk, the Holy Grail of Fashion, Became a Reality

Strong, sustainable and sophisticated: man has for centuries tried to farm spider silk, to no avail. But now one company has found a way to produce it artificially, and with serious environmental and health benefits, it’s set to become the material of the future. Lucy Ingham finds out more from David Breslauer of Bolt Threats  

For many years, spider silk has been recognised as something of a wonder material.

“Spider silk is biodegradable, hypoallergenic and antimicrobial. And it's not just one silk; spiders produce six different types of silk from six different glands in their tiny bodies,” summarises David Breslauer, CSO and co-founder of Bolt Threads, at a talk at Web Summit.

“It's probably the toughest, strongest and stretchiest material we know, fibre in particular, and that includes Kevlar. It's also made of protein, one of the building blocks of nature.”

However, attempts to extract spider silk for human use have by and large been wildly unsuccessful, which has shifted the focus to the emerging biological field of biomimicry: the attempt to replicate what is achieved in nature using technology.

This is no mean feat, so when Bolt Threads announced that it had successfully produced artificial spider silk threads, it was understandably met with considerable interest. However, while impressive on its own, the real impact is still to be realised: the complete transformation of the environmental footprint of our clothes.  

“Our clothes are killing us”: the textile industry’s environmental time bomb

Right now, much of what we wear is made from synthetic fibres, and while these fabrics have revolutionised the clothing industry, they also come with serious problems.

“You're all wearing synthetic fibres, whether it's your socks, your underwear, your shirts or your bra,” says Breslauer. “You have nylon or polyester on you and those fibres are great. They are lightweight, they dry quickly and they're cheap, if you don't count the environmental costs of drilling for oil. But they have a huge downside: they never go away.

“That island of plastic the size of Texas floating in the Pacific, a lot of that is your clothes. When your clothes are made of petroleum it takes nearly two hundred years to decompose. Think about that every time you throw one out.”

There's a great likelihood we all have little plastic fibers in our stomachs right now

But, argues Breslauer, the bigger problem is the threat that they pose to our health.

“Our clothes are killing us,” he says. 

“In 2012 Patagonia did a study that found every time you wash your fleece vest, little tiny microfibres escape from the washing machine, go into the ocean, plankton eat those fibres, fish eat the plankton and [we] eat the fish.”

A recent study by scientists at the National University of Ireland Galway supported this, finding that plastic was present in 73% of deep ocean fish.

“So there's a great likelihood we all have little plastic fibers in our stomachs right now. Now that could be inconsequential, we don't know, but my bet is that it's bad,” says Breslauer.

“What we do know is that this process is not sustainable. So we have two options as citizens of the planet: we either try to buck the entire capitalist system, or we can try to harness nature to create clothes that feed the environment rather than destroy it.”

Spider silk, Breslauer argues, is the more favourable solution, allowing us to continue the same buying habits without the environmental damage.

“Spider silk is made of protein and decomposes. It turns into nutrition for other microorganisms. Your worn out yoga clothes could actually feed life.”

Why can’t we farm spider silk?

If spider silk is such a good solution, why is it that it can’t be farmed?

“We farm silkworms to get silk threads, so why can't we just farm spiders in the same way?” asks Breslauer.

While undertaking his PhD he did, in fact, attempt this very feat, with less than desirable results.

“For hundreds of years man has tried to figure out to get silk from spiders en masse. Unfortunately spiders are not team players,” he says. “I was told back in the day that if I took hula hoops and put them up in my office, the spiders would just make webs in them.”

This is exactly what he did, but the results were not desirable.

“Over time they left the hula hoops. They slowly made their way around the office and then eventually they find each other, attack each other and kill each other,” he explains. “So that didn't work, and I didn't get very far.”

Making artificial spider silk a reality

Breslauer continued his research into spider silk, giving up on the real thing in favour of replicating the liquid protein produced by spiders and turning it into fibre. Unfortunately, while he cracked the fibre-forming part, he was not so successful in creating an artificial version of the protein.

However, fortuitously researchers at another nearby university had managed to do just that.

“I heard of two guys across the San Francisco Bay who were also obsessed with spider silk. Turns out they were trying to make that liquid protein using things found in nature, like yeast and sugar, but they couldn't turn this stuff into a fibre,” explains Breslauer. “This is great, right. I had what they needed, they had what I needed. So we got together and formed a company.”

Spider silk is incredibly tunable. We could tune it to decompose in five years or keep it preserved for up to 5,000


Bolt Threads was born, and spent the next few years refining the artificial spider silk manufacturing process, which is now a reality.

“We start by buying truckloads of corn that are turned into sugar, and we feed the sugar to a special yeast that we have modified over years to make spider silk,” he says.

“We grow this in gigantic fermenters the size of grain silos, five stories tall, 20ft in diameter.

“We then collect and purify the liquid silk and extruded through tiny, tiny holes. In this process you dry it into a solid and you stretch it, and you stretch it and you stretch it until it turns into a fine gossamer thread. You can then knit it or weave it just like any other fibre.”

The resulting fabric, which is easy to wash and wear without the care issues associated with conventional silk, can be tailored to the unique needs of its application.

“Spider silk is incredibly tunable. We could tune it to decompose in five years or keep it preserved for up to 5,000,” he explains. “And in fact if you take the liquid protein, you can make films, blocks, sponges or biocompatible scaffolds to grow tissues, or even glues for wound repair.”

The company's first commercial Product is a range of artificial spider silk ties, which retail for $314

Images courtesy of bolt Threads

Stella Mccartney's spider silk dress, which was displayed as part of an exhibition at MoMA

Bringing biomimicry to fashion

While others have announced solutions to the spider silk issue, Bolt Threads remain the only company to be producing artificial spider silk at a commercial scale, meaning it is a genuine option for mass consumer use.

And while the company is in the early stages of making this a reality, it has already taken the first steps towards introducing the fabric to the world of fashion.

The company released its first product last year, a limited run of ties produced entirely with spider silk, and has produced a number of other limited-edition products in partnership with various fashion brands.

Most notably, the company partnered with fashion designer Stella McCartney, in a venture that not only resulted in Bolt Threads fabric being featured in her 2017 Paris Fashion Week show, but also led to a dress designed by her being featured in an exhibition at New York Museum of Modern Art.

“It's made from 100% spider silk that we created in our laboratory in Emeryville, California – that's right outside San Francisco. It started as sugar and now I'd say it's a work of art,” says Breslauer.

More spider silk-based clothing is set to appear in the coming year, and with it – the company hopes – more awareness of the fabric. However, this hasn’t stopped it from considering other biomimetic options on the horizon.

“The desert ant, it lives in the Sahara where it's 120 degrees and their hairs keep it 10 degrees cooler than the environment. Imagine putting that in your yoga pants to keep you cooler on a sunny day,” muses Breslauer.

“Or the dragonfly, take that biorubber [in its wings] and put it in your shoes to give you an extra spring in your step when you're on a power walk.

“Or the mollusk. They use a protein-based glue to adhere themselves rocks under water – that glue is so strong they can withstand hurricanes. What if we held all our clothes together with a non-toxic, biodegradable adhesive?”

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