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Techbolt threads

Bolt Threads is recreating fabric from spider silk

By
Leena Rao
Leena Rao
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By
Leena Rao
Leena Rao
Down Arrow Button Icon
June 4, 2015, 7:30 AM ET

While in UC San Francisco’s Ph.D biochemistry and engineering program, Dan Widmaier, David Breslauer and Ethan Mirsky became fascinated with the idea of creating man-made silk from the protein fibers in the webs spiders make, called spider silk. In fact, spider silk is known to be five times stronger than steel, and tougher than man made fabric Kevlar.

The PhD students set out in 2009 to create a technology that makes these proteins without using spiders. After years in stealth research and production, Bolt Threads is finally debuting its proprietary engineered silk, along with announcing a new $32.3 million round in Series B funding.

Foundation Capital and Formation 8 co-led the round, with participation from Founders Fund. The company has raised a total of $40 million.

Bolt Threads uses proprietary technologies to create engineered silk fibers based on proteins found in spider silk that can be produced at commercial scale.

At a scientific level, Bolt actually examines the DNA of spiders and then replicates those genetic sequences in other ingredients to create a similar silk fiber.

Bolt’s silk is made primarily of sugar, water, salts and yeast, which combined makes a liquid silk protein. Through a process called wet spinning, this liquid is spun into fiber, similar to the way fibers like acrylic and rayon are made.
If you look under a microscope, says the company, Bolt’s engineered silk fibers have the exact same chemistry as naturally occurring animal silks from spiders or silk worms.

Widmaier explains that the silk fabric created by Bolt has similar qualities to conventional silk in that it will provide warmth, and a softer feel, but will be easier to wash and wear. For example, you won’t have to dry clean Bolt’s silk because it will have the durability to be washed in a machine. The company is working with textile manufacturers in North Carolina to commercially scale production of the fabric.

Bolt isn’t the only company to try to create spider silk at mass. Japanese startup Spiber is marketing a similar fiber. German company Amsilk is also developing commercial grad spider silk.

The company will be using the new funding to expand production and comercialization of its silk fabric.

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About the Author
By Leena Rao
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