Featured Research

from universities, journals, and other organizations

Nature Publishes Secret Of Abalone Shell Strength

Date:
June 30, 1999
Source:
University Of California, Santa Barbara
Summary:
Researchers have cracked the mystery of the abalone shell's toughness and fracture resistance, according to the June 24 issue of the journal Nature. It's all in the stretch, according to the discovery made at the University of California, Santa Barbara, by a team of physicists, molecular biologists and chemists.

Researchers have cracked the mystery of the abalone shell's toughness and fracture resistance, according to the June 24 issue of the journal Nature.

It's all in the stretch, according to the discovery made at the University of California, Santa Barbara, by a team of physicists, molecular biologists and chemists.

The discovery suggests a new kind of biological "rubber" and helps explain the exceptional strength of the plywood-like structure of the abalone shell.

"Now that we've elucidated some of nature's secrets, we can begin to mimic these design patterns," said Bettye L. Smith, research associate in the Department of Physics, and lead author, who is working toward designing and synthesizing strong and tough fibers based on nature's design.

The abalone shell is roughly 3,000 times more fracture resistant than a single crystal of calcium carbonate, the mineral that makes up most of its bulk. The UC Santa Barbara experiments show that the mechanism behind the fracture resistance is in the polymer adhesive that holds the crystal tablets together.

The researchers were able to reveal the properties of the adhesive in single-molecule pulling experiments using the Atomic Force Microscope (AFM) to measure the elasticity and strength of individual protein molecules. This work was done under the direction of Paul K. Hansma, professor of physics, by his laboratory group. (Hansma is a major developer of new techniques using the AFM.)

"By grabbing a single molecule and pulling on it as if it were a rubber band, you can measure the strength of a single molecular fiber," said Smith.

"Using this technique they discovered that the tiny crystal plates of mineral that make up the abalone shell are held together with many molecules of a protein that have a truly enormous capacity to absorb shock without breaking," said Dan Morse, professor of molecular genetics and biochemistry and chairman of the Marine Biotechnology Center.

"From studies in our lab in which we cloned the gene that codes for this protein, we're able to see a unique 'modular' structure that makes the protein look like a series of springs or shock absorbers linked together," said Morse.

The experiments revealed that these springs are uncoiled when the molecule is stressed, letting go one at a time, said Smith. "Remarkably, when the stress is relaxed, they coil back, recovering their original structure."

These "sacrificial" links break in response to stress before the whole molecule breaks, thus protecting the whole molecule. And these "sacrificial" links can reform when the stress is gone, explained Hansma.

Fibers produced synthetically are either very strong like Kevlar - used in bulletproof vests - or tough and elastic like silicon rubber, but very few combine both properties.

"These findings are nature's secret of how to build fibers that are simultaneously strong and elastically tough at the same time," said Smith. "We hope that by applying the secret to the synthesis of new materials, that we'll be able to produce inexpensive fibers that are tailored to tough and strong high performance applications."

Possible applications of such fibers include usage in textiles, ropes, construction materials, aeronautics, camping gear, and biomedical applications such as implant materials and prosthetics.

Authors of the Nature article, 'Molecular Mechanistic Origin of the Toughness of Natural Adhesives, Fibers, and Composites,' are Bettye L. Smith, research associate, Department of Physics, UCSB; Tilman E. Schaffer, assistant professor, Department of Molecular Biology, Max-Planck-Institute for Biophysical Chemistry, Germany (and former graduate student, Department of Physics, UCSB); Mario Viani, graduate student, Department of Physics, UCSB; James B. Thompson, graduate student, Department of Physics, UCSB; Neil A Frederick, undergraduate, Department of Physics, UCSB; Johannes Kindt, graduate student, Department of Physics, UCSB; Angela Belcher, assistant professor, Department of Chemistry, University of Texas, (and former graduate student, Department of Chemistry, UCSB); Galen D. Stucky, professor of chemistry and materials, UCSB; Daniel E. Morse, professor of molecular genetics and biochemistry, and chairman, Marine Biotechnology Center, UCSB; and Paul K. Hansma, professor of physics, UCSB.


Story Source:

The above story is based on materials provided by University Of California, Santa Barbara. Note: Materials may be edited for content and length.


Cite This Page:

University Of California, Santa Barbara. "Nature Publishes Secret Of Abalone Shell Strength." ScienceDaily. ScienceDaily, 30 June 1999. <www.sciencedaily.com/releases/1999/06/990630072943.htm>.
University Of California, Santa Barbara. (1999, June 30). Nature Publishes Secret Of Abalone Shell Strength. ScienceDaily. Retrieved August 23, 2014 from www.sciencedaily.com/releases/1999/06/990630072943.htm
University Of California, Santa Barbara. "Nature Publishes Secret Of Abalone Shell Strength." ScienceDaily. www.sciencedaily.com/releases/1999/06/990630072943.htm (accessed August 23, 2014).

Share This




More Matter & Energy News

Saturday, August 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Is It a Plane? No, It's a Hoverbike

Is It a Plane? No, It's a Hoverbike

Reuters - Business Video Online (Aug. 22, 2014) UK-based Malloy Aeronautics is preparing to test a manned quadcopter capable of out-manouvering a helicopter and presenting a new paradigm for aerial vehicles. A 1/3-sized scale model is already gaining popularity with drone enthusiasts around the world, with the full-sized manned model expected to take flight in the near future. Matthew Stock reports. Video provided by Reuters
Powered by NewsLook.com
Coal Gas Boom in China Holds Climate Risks

Coal Gas Boom in China Holds Climate Risks

AP (Aug. 22, 2014) China's energy revolution could do more harm than good for the environment, despite the country's commitment to reducing pollution and curbing its carbon emissions. (Aug. 22) Video provided by AP
Powered by NewsLook.com
Former TSA X-Ray Scanners Easily Tricked To Miss Weapons

Former TSA X-Ray Scanners Easily Tricked To Miss Weapons

Newsy (Aug. 21, 2014) Researchers found the scanners could be duped simply by placing a weapon off to the side of the body or encasing it under a plastic shield. Video provided by Newsy
Powered by NewsLook.com
Flower Power! Dandelions Make Car Tires?

Flower Power! Dandelions Make Car Tires?

Reuters - Business Video Online (Aug. 20, 2014) Forget rolling on rubber, could car drivers soon be traveling on tires made from dandelions? Teams of scientists are racing to breed a type of the yellow flower whose taproot has a milky fluid with tire-grade rubber particles in it. As Joanna Partridge reports, global tire makers are investing millions in research into a new tire source. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins