Research reveals efficiency of spider fangs in cutting high-strength fibers

A study conducted by a team of scientists from the University of Trento, in partnership with the Swedish University of Agricultural Sciences, revealed how spiders use serrated fangs to cut one of the strongest biological materials: silk. This discovery also explains how these fangs can cut high-performance synthetic fibers, such as carbon and Kevlar.

The research challenges the prevailing view that spiders rely solely on digestive enzymes to dissolve silk and other tough materials. While chemistry plays a role in the process, the study showed that the cutting efficiency actually lies in the mechanical structure of the spiders’ fangs. The fangs feature microserrations, which act like finely tuned blades to cut fibers with precision. The serrations create stress concentration points, making it easier to cut with less force, something that was not fully understood until now.

The team, led by researchers Nicola Pugno and Gabriele Greco, tested the spiders’ cutting abilities using carbon and Kevlar fibers, as well as silk. The study showed that the spiders’ fangs have a functionally graduated spacing between the serrations, allowing the fiber to slide until it fits into the ideal cutting point. When this occurs, the force required to cut the fiber is minimal. This mechanism proved to be more efficient than a standard razor blade.

The study offers a new perspective on cutting mechanisms that occur in nature, providing insights for both biologists and engineers. Scientists believe that this discovery could inspire the development of more efficient and precise cutting tools.

"This new theory could help us create sharper, more effective tools, such as saws and knives, based on the design of spider fangs," Pugno explained. "Applications could range from cutting wood, metals and stones to food and hair."

The discovery reinforces the importance of looking to nature to solve technical problems. Just as spider silk inspired the creation of stronger synthetic fibers, spider fangs could pave the way for advances in the manufacture of blades and other cutting tools.

More information can be found at doi.org/10.1002/advs.202406079