Spider Silk is Tougher Than Steel?

THE superior properties of natural spider silks are well known, and now efforts to use them to produce body armour are underway. The production of spider silk in commercial quantities holds the potential of a life-saving ballistic resistant material, which is lighter, thinner, more flexible, and tougher than steel.

So much so the US Army’s Soldier Protection and Individual Equipment Office has been funding research into the application of spider silk. The basic challenge lies in that spider are cannibalistic in nature and cannot be raised in concentrated colonies to produce silk in commercial quantities.

The global market demand for technical fibres is growing rapidly and these materials have become essential products for both industrial and consumer applications. By 2012, the annual global market for technical fibres had already reached approximately US$133 billion.

While scientists have been able to replicate the proteins that are the building blocks of spider silk, two technological barriers have stymied production. These barriers are the inability to form these proteins into a spider silk fibre with the desired mechanical characteristics, and to do this cost effectively.

To solve these problems, Kraig Biocraft Laboratories invented a new technology and acquired the exclusive right to use the patented genetic sequences for numerous fundamental spider silk proteins.

Kraig considers itself a world leader in genetically engineered spider silk technologies by applying proprietary genetic engineering spider silk technology to an organism which is already one of the most efficient commercial producers of silk: the domesticated silkworm.

Its spider silk technology builds upon the unique advantages of the domesticated silkworm for this application. The silkworm is ideally suited to produce genetically engineered spider silk because it is already an efficient commercial and industrial producer of silk.

Some 40% of the caterpillars’ weight is devoted to the silk glands. The silk glands produce large volumes of protein, called fibroin, which are then spun into a composite protein thread or silk.


Kraig is focused on the creation, production and marketing of high performance and technical fibres such as spider silk. Because spider silks are stronger and tougher than steel, they could be used in a wide variety of military, industrial, and consumer applications ranging from ballistic protection to superior strength and toughness.

However, there is another player offering sustainable and high performance fabrics. Bolt Threads, an American-based biotechnology company, recently raised US$50 million in Series C financing.

Since launching out of stealth in 2015, Bolt Threads has attracted the interest of both new investors and partners. The company is now producing its Engineered Silk protein at large scale, and is moving into yarn manufacturing this summer.

Bolt Threads was co-founded in 2009 by CEO Dan Widmaier, chief scientific officer David Breslauer, and vice-president of operations Ethan Mirsky. The three were fascinated with natural silk, its properties and the process of its production in nature. This curiosity led them to develop technology to produce Engineered Silk made wholly of natural proteins, creating a sustainable and durable new material. Together with partners like Patagonia, Bolt Threads is pioneering more sustainable and non-toxic processes for textile manufacturing.

“Man-made fabrics like nylon and polyester have transformed the fashion industry, for better and for worse,” said Widmaier. “The use of hydrocarbon polymers in these textiles has created a lingering toxic problem for the environment. At Bolt Threads, we’re re-thinking textile manufacturing, producing high performance materials that are also not nearly as harmful to the environment as existing options.”

Bolt Threads researchers originally studied real spiders’ silk, to understand the relationship between the spiders’ DNA and the characteristics of the fibres they make. Today’s technology allows them to make those proteins without using spiders.

After the studying of spider DNA, researchers then create sequences engineered for commercial production while keeping costs down. Primarily the fabric fibres are made of sugar, water, salts and yeast. The yeast produces silk protein in a liquid form during fermentation — very much like the beer-making process. After some processing, the liquid silk protein can be turned into fibre through wetspinning, which is the same way fibres like acrylic and rayon are made.

The company envisions to produce iPad covers, car seats and even name-brand clothing starting 2017.