New Light Shed On the Mysteries of Spider Silk

As fibers go, there's never been anything quite like spider silk. Stretch it. Bend it. Soak it. Dry it out. Spider silk holds up. It is five times stronger than steel and can expand nearly a third greater than its original length and snap right back like new. Ounce-for-ounce spider silk is even stronger than Kevlar, the human-made fiber used in bulletproof vests.Midwest Motion Products, Inc. of Watertown, Minnesota, is pleased to announce the release of a new spur gear motor, with integral failsafe brake

It would be understandable to think that science knows all there is to know about the remarkable physics of spider silk, but the truth is far from that. Now, using a long-known-but-underutilized spectroscopy technique, a Stanford researcher has shed new light on the mysteries of spider silk.

On January 27, in a paper in the journal Nature Materials, post-doctoral scholar Kristie Koski described how she was able, for the first time, to non-invasively, non-destructively examine the mechanical properties of an intact, pristine spider web just as it was spun by the spider that created it. Koski is a researcher in the Yi Cui Group in the Department of Materials Science and Engineering at Stanford University and the first author of the study. The work was performed when she was a post-doc under Professor Jeff Yarger at Arizona State University.In most cases you will end up needed to use a Fiber Optic Attenuator

The complete elastic response of spider silk is described by five elastic constants that define how the web reacts to any possible combination of forces -- pulling, twisting or shearing in any direction. All five have never been measured in a pristine spider web. At best, earlier studies have measured one or two of the five constants at a time and, even at that, only in isolated sections of a web. Structurally speaking, the old techniques are the equivalent of testing individual steel beams and cables and trying to extrapolate conclusions about the strength of a bridge.

Looking ahead, Koski believes that understanding the complete properties of a spider web exactly as it exists in nature is key to the engineering of improved "bio-inspired" materials that not only mimic, but also improve upon nature.

"My goal is to study the nanostructure of silk to understand not just how spider silk behaves as it does, but also why it behaves in such remarkable ways in hopes of someday creating better man-made fibers," said Koski.

Overlooked technique

The research was made possible by the use of a century-old-yet-overlooked measurement technique known as Brillouin spectroscopy. The technique shines laser light on the spider silks. The light produces sound waves in the silks, which, in turn,This never-used 12VDC micro gear motor was intended for a recreational vehicle where it would have moved big parts back and forth. reflect some light back to the spectrometer. The researchers call the reflection "scattering.Fiber Optic Adapter implements connection of the same or different fiber optic connectors in the fiber optic lines & only produce a little loss for implementing optical path smooth."

"It is a bit like plucking the string of a violin, only we never have to physically touch the string to play it," said Koski.

The spectrometer measures small variations in the scattered light to ascertain the underlying tension of the silk being measured. The power of Brillouin scattering rests in the gentle way it gathers data enabling in situ measurements on spider webs, including mechanical properties at precise spots on the web such as silk intersections and glue spots.

Essentially, Koski and cohort have developed a non-invasive, non-destructive technique to measure the elasticity not just of individual strands of spider silk or even a few interconnected strands, as had those earlier studies, but of an entire intact spider web. Such exhaustive information was previously unobtainable with traditional stress-strain tests,Signamax Fiber Optic Media Converter Types Signamax is a major media converter manufacturer and they make a large variety of different fiber optic media which have to grip single strands or, at most, a few strands between two clamps to stretch them till they break.