A powerful spider silk fiber with super-stretchability

A team of architects and chemists from the University of Cambridge designed a strong ductile fiber, mostly made of water, which can be used to make fabrics, sensors and other materials. This fiber, because it absorbs a lot of energy, is like a miniature elastic rope, a sustainable non-toxic fiber that can be made at room temperature.

This new method not only improves on the previous method of making synthetic spider silk, it does not require high-energy procedures or harmful solvents, but also greatly improves the method of manufacturing all kinds of synthetic fibers, because other types of synthetic fibers also rely on high energy, Poisonous method. This achievement has been published in the Proceedings of the National Academy of Sciences.

Spider silk is one of the toughest materials in nature. Scientists try to simulate their properties and apply them in a large number of applications with varying degrees of success. Dr. Darshil Shah, co-author of the Department of Architecture at Cambridge University, said: "We have not completely reconstructed the elegance of spider silk."

The fiber designed by the Cambridge team was "spun" from a paste called hydrogel, 98% of which is water. The remaining 2% consists of silica and cellulose, both of which are available in nature and are joined together by a tubular molecule called "handcuffs" called melon rings. The chemical interaction between the different components allows a long fiber to be drawn from the gel.

These fibers are extracted from the hydrogel to form long, thin, thin lines of only one millionth of a meter. After about 30 seconds, the water evaporates and the rest is a tough and ductile fiber.

Shah said: "Although our fibers are not as strong as the spider silk, they can support pressures from 100 to 150 MPa, similar to other synthetic and natural silks. But our fibers are non-toxic and not manufactured. How to consume energy."

The fibers self-assemble at room temperature and are combined by supramolecular host-guest chemistry, which relies on weak interactions between molecules rather than covalent bonds of atoms sharing electrons.

Yuchao Wu, Ph.D., Ph.D., Ph.D., Department of Chemistry, University of Cambridge, said: “When you look at these fibers, you can find the different forces that combine them at different scales. It’s like a hierarchical structure that creates complexity. The nature of the combination."

The strength of this fiber exceeds that of other synthetic fibers, such as cellulose-based viscose and rayon, and also exceeds natural fibers such as human or animal hair.

In addition to strength, the fibers also exhibit very high shock absorption, meaning they absorb a lot of energy, like a stretch rope. There are currently no synthetic fibers with this ability, but high damping is one of the characteristics of spider silk. Researchers have found that the shock-absorbing capacity of this fiber exceeds natural silk in some cases.

Shah said: “We believe that this fiber manufacturing method can be a sustainable alternative to current manufacturing methods.” Researchers plan to further explore the chemical properties of this fiber, including the manufacture of yarns and woven fibers.