What is it?
Taking inspiration from spiders and their soft yet durable threads, Bolt Threads is working on Microsilk™, a biosynthetic fiber. Supposed to be “warmer than wool and stronger than silk,” Microsilk is a lightweight material that can biodegrade by the end of its life cycle.

What makes it?
Work is being done in Bolt Threads’ three locations, Arnhem in the Netherlands, Portland and San Francisco in the US, to deliver their spin this fiber into actuality. In their 32-square-foot facility in San Francisco, their science labs are dedicated to concocting the perfect ingredient for a fabric that is “stronger than steel and more tear-resistant than Kevlar.”
The team behind Microsilk has been at it since day 1. Founded in 2009 by an international team of bioscientists, Bolt Threads has since garnered steam to push its passion project. After raising over $200 million worth of investment, the company has since focused its energies on refining the technology.

How is it made?
Although inspired by spiders, Bolt Threads has no intentions of recruiting a single spider into their ranks. Rather, their technology is based on bio-mimicry: they aim to study their silk proteins and then produce bioengineered yeasts capable of producing these spider silk-like proteins. Bolt Threads then plans to ferment metric tons of yeast by feeding them sugar and water. In short, it is more like making beer than keeping spiders in a cellar. So far, no arachnids were harmed in the process.
Bolt Threads’ tech also strives to be ecologically responsible by relying on renewable sugar which can be grown and replanted. Moreover, unlike polyesters which are based on non-renewable petroleum derivatives, Microsilk is protein-based. Therefore, it can breakdown and leave no trace in nature.

Which brands use it?
Although still in the research and development stage, Microsilk has already been featured in several prototypes. For instance, in 2017, Bolt Threads worked with designer Stella McCartney to come up with a marvelous shift dress which was exhibited in New York MoMA. Moreover, in 2019, in collaboration with Stella McCartney and adidas, Bolt Threads created the Biofabric Tennis Dress, a biodegradable apparel made out of Microsilk and cellulose blend fiber.

All these testify to the fact that there is a growing interest in biosynthetic and environmentally-friendly textile materials. As Bolt Threads continues to develop its product, we should hope that more innovators look towards the natural world for creative inspiration.