Scientists from Arizona State University have unraveled the mysteries of spider silk using a laser light scattering technique.
“Spider silk has a unique combination of mechanical strength and elasticity that make it one of the toughest materials we know,” said lead researcher Jeffery Yarger of Arizona State University’s Department of Chemistry and Biochemistry, in a statement. “This work represents the most complete understanding we have of the underlying mechanical properties of spider silks.”
Spider silk is an amazing biological polymer, according to scientists. Yarger and his colleagues are examining its molecular structure in an attempt to create materials ranging from bulletproof vests to artificial tendons.
This is the first time that scientists have successfully determined the elastic and mechanical properties of spider silk. Scientists believe that their findings will aid future modeling efforts designed to flesh out the interaction of the mechanical properties and the molecular structure of silk used to generate spider webs.
“This information should help provide a blueprint for structural engineering of an abundant array of bio-inspired materials, such as precise materials engineering of synthetic fibers to create stronger, stretchier, and more elastic materials,” said Yarger.
Scientists recorded what happened to an extremely lower power laser (less than 3.5 milliwatts) as it passed through the spider webs. This test allowed scientists to spatially map the elastic stiffnesses of each web without disturbing it. They found variations among discrete fibers, junctions and glue spots.
Scientists examined several different types of spider’s webs, including Nephila clavipes, A. aurantia, L. Hesperus and P. viridans.
They also looked into one of the must studied aspects of orb-weaving dragline spider silk, called supercontraction. This property, which is unique to silk, leads to significant shrinkage in an unrestrained dragline fiber.
Their results confirm the hypothesis that supercontraction helps the spider adapt the properties of the silk during the spinning process.
“This study is unique in that we can extract all the elastic properties of spider silk that cannot and have not been measured with conventional testing,” said Yarger.
The study’s findings were recently published in the journal Nature materials.
Photo credit: Jeffery Yarger.