Chemists Use Laser Scattering Technique to Capture the Unique Properties of Spider Silk

29 January 2013

Using a complex but non-invasive laser light scattering technique, scientists have come closer to understanding the mystery of the unique mechanical strength and elasticity of spider silk, the characteristics that make it one of the strongest materials ever known.

Through the Brillouin light scattering technique using an extremely low power laser, less than 3.5 milliwatts, chemists at Arizona State University, led by Professor Jeffery Yarger, obtained a wide array of elastic and mechanical properties of the silk of several intact spider webs. Recording what happened to the laser beam as it passed the spider webs enabled researchers to spatially map the elastic stiffness of each web while keeping the web intact. The no-contact measurement showed variations among discrete fibers, junctions and glue spots. Thus, the scientists have made significant progress in understanding the molecular structure of spider silk, an exceptional biological polymer linked to collagen but with a much more complex make-up.

The variety of properties of spider silk in situ, obtained by the team of chemists at Arizona, will help provide a blueprint for structural engineering to create stretchier, stronger and more elastic materials, Prof Yarger said.

The team studied four different types of spider webs as well as supercontraction, or the significant shrinking in dragline spider silk when exposed to humidity. The results of the study confirmed the assumption that supercontraction helps the spider tailor the silk properties during spinning, a behavior that provides valuable insight related to bio-inspired mechanical structure.