Scientists unravel the mysterious mechanics of spider silk

Mar 01, 2011

Scientists now have a better understanding of why spider silk fibers are so incredibly strong. Recent research, published by Cell Press on February 15th in Biophysical Journal, describes the architecture of silk fibers from the atomic level up and reveals new information about the molecular structure that underlies the amazing mechanical characteristics of this fascinating natural material.

Spiders spin silk, which is remarkably strong and stretchy, to use in webs and to suspend themselves. "Silk fibers exhibit astonishing . They have an ultimate strength comparable to steel, toughness greater than Kevlar and a less than cotton or nylon," explains senior study author Dr. Frauke Gräter from the Heidelberg Institute for Theoretical Studies in Germany. "Because silk fibers continue to outperform their artificial counterparts in terms of toughness, many studies have tried to understand the mechanical characteristics of these extraordinary natural fibers."

Scientists know that spider silk fibers consist of two types of building blocks, soft amorphous and strong crystalline components. Dr. Gräter's group wanted to develop a better understanding of the mechanical properties of spider silk fibers and implemented a multi-scale "bottom-up" computational approach that started at the level of the atoms that make up the amorphous and crystalline subunits and dissected the contributions of these building blocks. The group used both molecular simulations for studying individual and coupled subunits and finite element simulations for a comprehensive fiber model.

The researchers discovered that the soft amorphous subunits are responsible for the elasticity of silk and also help with the distribution of stress. The maximal toughness of silk requires a specific amount of crystalline subunits and is dependent on the way that these subunits are distributed in the fiber. Different structural architectures of the fiber subunits were tested for optimal mechanical performance.

"We determined that a serial arrangement of the crystalline and amorphous subunits in discs outperformed a random or parallel arrangement, suggesting a new structural model for silk," says Dr. Gräter. Taken together, the findings provide a clearer understanding of the mechanical nature of fibers and may be useful for design of artificial silk fibers.

Explore further: Can perovskites and silicon team up to boost industrial solar cell efficiencies?

add to favorites email to friend print save as pdf

Related Stories

Stretchy spider silks can be springs or rubber

May 31, 2008

It’s stronger than steel and nylon, and more extensible than Kevlar. So what is this super-tough material? Spider silk; and learning how to spin it is one of the materials industries’ Holy Grails. John Gosline has been ...

Scientists breed goats that produce spider silk

May 31, 2010

(PhysOrg.com) -- Researchers from the University of Wyoming have developed a way to incorporate spiders' silk-spinning genes into goats, allowing the researchers to harvest the silk protein from the goats’ ...

Recommended for you

New insights found in black hole collisions

Mar 27, 2015

New research provides revelations about the most energetic event in the universe—the merging of two spinning, orbiting black holes into a much larger black hole.

X-rays probe LHC for cause of short circuit

Mar 27, 2015

The LHC has now transitioned from powering tests to the machine checkout phase. This phase involves the full-scale tests of all systems in preparation for beam. Early last Saturday morning, during the ramp-down, ...

Swimming algae offer insights into living fluid dynamics

Mar 27, 2015

None of us would be alive if sperm cells didn't know how to swim, or if the cilia in our lungs couldn't prevent fluid buildup. But we know very little about the dynamics of so-called "living fluids," those ...

First glimpse inside a macroscopic quantum state

Mar 27, 2015

In a recent study published in Physical Review Letters, the research group led by ICREA Prof at ICFO Morgan Mitchell has detected, for the first time, entanglement among individual photon pairs in a beam ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.