Nature as a Role Model: Artificial Spider Silk for Textiles
Bionic High-Performance Fiber Biosteel
Tough, elastic and resilient: Its outstanding properties make spider silk equally interesting to biologists and product designers. A German company has been successful in producing this fiber artificially. The material is named “Biosteel”, and it is designed for applications in high-tech textiles, for example in the areas of sports, medicine and military.
Spiders are specialized in silk. Each of the 41,000 spider species has its own set of silk threads at its disposal. Spider silks can be stiffer than steel and as elastic as rubber. They are fully recyclable, lightweight and waterproof, even though their reversible water absorption capacity is high.
While spiders are unsuitable as breeding animals, it has long been impossible to generate such threads industrially. Since the 1980ies, scientist have therefore been looking into ways to integrate the genetic information of spider silk into industrially producible microorganisms such as yeasts or bacteria, in order to obtain spider silk proteins in a biotechnological way.
The way in which spiders spin their nets has been a fascinating question, also to Professor Thomas Scheibel. He holds the chair of Biomaterials at the University of Bayreuth and is founder of AMSilk GmbH in Planegg near Munich, Germany. The biochemist set his mind on finding out about the chemical and mechanical processes taking place when the silk threads are produced. He aimed at finding a way to copy them technically and he has reached this target. Together with working groups of the TUM University of Munich - Prof. Andreas Bausch and Horst Kessler of the Institute for Advances Study of the TUM - Scheibel’s team was successful in building an artificial spinning duct for the first time in 2008.
Two years later, the scientists decoded the molecular basis of thread production in the spinneret. In 2011, they were finally able to show the mechanisms leading to the enormous stiffness of the spider silk thread. The first artificial spider silk fiber of the world they eventually presented in 2013, under the name of “Biosteel”. The same year, Scheibel obtained the Dechma-Prize awarded by the Max Buchner Research Foundation.
The Name Says it All
Biosteel fibers are generated in a scalable spinning process. According to AMSilk information, the bionic high-performance fiber is completely biodegradable. The company states that, in addition, the fibers are similar to wool in that they are able to absorb and pass on humidity and have anti-microbacterial properties besides being tough and eudermic.
The fiber is up to 15% lighter than conventional synthetic fibers, and the producer claims that at present there is no other natural material available with a higher strength. Its load-bearing capacity is said to be 25 times as high as that of a comparable steel wire. According to the scientists, standard dyeing techniques are sufficient to color the fibers. The artificial fibers’ tensile strength is comparable to that of natural silk and to the filaments of the silkworm, while its load-bearing capacity is as much as twice as high.
Partnership with adidas
From using novelties such as 3-D printing up to processing waste from oceans – adidas AG in Herzogenaurach, Germany, has shown several times that it likes to strike new paths in shoe production. At the Biofabricate conference held in New York in November, the manufacturer of sports equipment presented the first ever performance shoe made of biosteel fibers. The upper of the Futurecraft-Biofabric shoe is 100% artificial silk.
It is uncertain, however, if or when the sneakers will actually be available to customers. For the time being, the shoes are mere prototypes. As part of their cooperation, the two enterprises have agreed to investigate ways of applying the Biosteel fibers at a larger scale.