Artificial silk that's tough like steel

Outside of Munich, in the "science suburb" of Martinsried silk is being manufactured from bacteria. A small industrial biotechnology company named AMSilk, founded in 2008 and staffed with around 30 employees, has developed a way to produce synthetic spider silk by genetically manipulating E. coli bacteria.

Based on traditional fermentation techniques already established in the chemicals industry, bacteria is enhanced with engineered spider silk DNA and programmed to produce fibroin (the raw material of silk) in large bioreactors. This raw material is then purified by a proprietary purification processes. The result is a dry white powder, used for several of AMSilk’s products. The process was inspired by the research of Thomas Scheibel, Professor of Biomaterials at the University of Bayreuth.

AMSilk calls the synthetic product Biosteel. “It’s about taking the best from nature and using it in industrial-scale production,” said CEO Jens Klein. Unlike the laboratory version, natural spider silk cannot be produced at an industrial scale, and its quality fluctuates.

Biosteel is heat-resistant, four times as tough as steel and three times more stretchable than a spider’s weavings. It is softer to the touch and more flexible, too. Above all, it is 100 percent biodegradable.

New sustainable materials are a hot topic in Germany's garment industry, notably in the outdoor and sporting goods sector. Customers want functional, durable clothing that dries quickly, and they won’t shy away from shelling out a few hundred euros for a jacket manufactured in an environmentally friendly manner.

AMSilk has wrapped up its research and development but isn’t yet off the blocks with marketing. Klein said the company is talking with several potential partners, including Adidas. A few months ago in New York, the sporting goods manufacturer presented the prototype for a shoe manufactured using Biosteel. The Futurecraft Biofabric model contains 100 percent biodegradable materials, with the upper made entirely of Biosteel fibers. Working with AMSilk “allows us to attain an incomparably high degree of sustainability,” said James Carnes, VP of Global Brand Strategy at Adidas, and the company is studying how to use Biosteel on a larger scale.

Though AMSilk has two dozen patents, the risk from competitors is very real, since a range of start-ups are working on similar developments. For example, outdoor product company The North Face has developed a parka made from artificial spider silk with the Japanese startup Spiber Inc. However, these projects have remained in the pilot phase, designed to show what is possible, since the material still comes with a hefty price tag. Opinion on whether or not variants of synthetic silk will conquer the market is divided. For AMSilk, production remains pricey, mainly down to the company currently producing in small amounts. The German start-up hopes that expanding to industrial scale production will lower costs. They argue that compared to other fibers, Biosteel adds value to performance products, and that when produced on a larger scale their product will be cost competitive with common fibers used in the shoe or garment industry.

AMSilk is financed by two institutional investors, AT Newtec and MIG funds. In total, the company’s technology has attracted investments running into tens of millions of euros. Strategically, the company needs to develop more uses for its silk such as speciality chemicals. It is collaborating with top Swiss medical and cosmetics company Rahn AG to produce a range of skin care products, and is planning to start working on human implants.

Klein remains confident: “In a few years time, you will be able to walk through the textiles, sport or cosmetics sections of a department store and find our products everywhere.”