Spider silk reveals a paradox of super-strength

Since its development in China thousands of years ago, silk from silkworms, spiders and other insects has been used for high-end, luxury fabrics as well as for parachutes and medical sutures. Now, National Science Foundation-supported researchers are untangling some of its most closely guarded secrets, and explaining why silk is so super strong.

Researchers at the Massachusetts Institute of Technology's Center for Materials Science and Engineering say the key to silk's pound-for-pound toughness, which exceeds that of steel, is its beta-sheet crystals, the nano-sized cross-linking domains that hold the material together.

Markus Buehler, the Esther and Harold E. Edgerton Associate Professor in MIT's department of civil and environmental engineering, and his team recently used computer models to simulate exactly how the components of beta sheet crystals move and interact with each other. They found that an unusual arrangement of hydrogen bonds–the “glue” that stabilizes the beta-sheet crystals–play an important role in defining the strength of silk.

They found that hydrogen bonds, which are among the weakest types of chemical bonds, gain strength when confined to spaces on the order of a few nanometers in size. Once in close proximity, the hydrogen bonds work together and become extremely strong. Moreover, if a hydrogen bond breaks, there are still many hydrogen bonds left that can contribute to the material's overall strength, due to their ability to “self-heal” the beta-sheet crystals.

The researchers conclude that silk's strength and ductility–its ability to bend or stretch without breaking–results from this peculiar arrangement of atomic bonds. They say controlling the size of the area in which hydrogen or other chemical bonds act can lead to significantly enhanced properties for future materials, even when the initial chemical bonds are very weak.

The journal Nature Materials reported the findings online March 14.

Media Contact

Bobbie Mixon EurekAlert!

More Information:

http://www.nsf.gov

All latest news from the category: Materials Sciences

Materials management deals with the research, development, manufacturing and processing of raw and industrial materials. Key aspects here are biological and medical issues, which play an increasingly important role in this field.

innovations-report offers in-depth articles related to the development and application of materials and the structure and properties of new materials.

Back to home

Comments (0)

Write a comment

Newest articles

Properties of new materials for microchips

… can now be measured well. Reseachers of Delft University of Technology demonstrated measuring performance properties of ultrathin silicon membranes. Making ever smaller and more powerful chips requires new ultrathin…

Floating solar’s potential

… to support sustainable development by addressing climate, water, and energy goals holistically. A new study published this week in Nature Energy raises the potential for floating solar photovoltaics (FPV)…

Skyrmions move at record speeds

… a step towards the computing of the future. An international research team led by scientists from the CNRS1 has discovered that the magnetic nanobubbles2 known as skyrmions can be…

Partners & Sponsors