Chinese researchers claim to have created silk up to 70% stronger than that produced by spiders and other silkworms.
According to the team of scientists, their “artificial super silk” is not only resilient but also safe for use in many industries, including textiles and medicine.
Silk has been cultivated in China since the Neolithic era, roughly 6 000 years ago, by the Yangshao culture, a proto-Chinese people who dwelt along the middle reaches of the country’s mighty Yellow River in modern-day Henan.
Common mulberry silkworms have traditionally been favoured amongst silk farmers because of their plentiful supply. Not all silks are created equal, however.
Silk spun from spiders, particularly dragline silk (the threads spiders use to seemingly suspend themselves in mid-air), is far more robust than that created by silkworms.
While arachnid silk has superior qualities, spiders are fiercely territorial and for this reason, are unsuited to farming.
Researchers have attempted to create hybrid silkworms, imbued with spider DNA, but the process is both expensive and complex.
Enter the scientists at Tianjin University and Ningxia Medical University: their recently completed study, published in the peer-reviewed journal, Matter, presented a novel method formulated by the research unit that sees ordinary silkworm silk processed to create a product significantly stronger than spider silk.
The newly harvested silk is washed in a chemical bath that actively cleans off the “glue” surrounding the core fibre. This glue-like texture that gives silk its sticky property is considered undesirable because it interferes with the spinning process and degrades the silk’s proteins.
When cleaned – and less inclined to clump and tangle – the silk is treated in a mixture of sugars, iron and zinc.
Once manually spun, the silkworm silk is incredibly fine, closely matching the thinness of spider’s silk at only a few microns in diameter, but was substantially stronger than both natural and dragline silk by some margin.
Scientists working on the project believe their creation shatters the myth that silkworm silk could never match the “mechanical performance” of their arachnid-based counterparts.
In their report, the researchers discuss their findings to create a market for high-performance, silk-based materials at scale.
Lin Zhi, a senior author of the paper dedicated to the study and biochemist at Tianjin University, told the press he and his team were already developing the second generation of chemically altered silks. With a more efficient, automated spinning technique, yields would be greatly boosted and production costs lowered.
Li said if he and his colleagues could secure more funding, they could hasten the development of high-strength, eco-friendly, silk-based biomaterials.