travis

Police officers and soldiers walking in the line of fire may one day want to stop and thank the abalone. That is because engineering researchers at the University of California, San Diego (UCSD) are using the shell of the seaweed-eating snail in an effort to develop a new generation of bullet-stopping armor.

The colorful oval shell of the red abalone is highly prized as a source of nacre, or mother-of-pearl, jewelry, but the researchers found another non-cosmetic use—the shell has an incredible ability to absorb heavy blows without breaking.

The abalone produces a helmet-like home made with 95% calcium carbonate "tiles" and 5% protein adhesive, said Marc A. Meyers, a professor in UCSD's Jacobs School of Engineering, and engineering graduate student Albert Lin.

The highly ordered brick-like tiled structure created by the mollusk is the toughest arrangement of tiles theoretically possible, the researchers said.

An abalone shell can't stop an AK47 bullet. However, laminates of aluminum and other materials have been disappointing as armors. Meyers said a careful examination of the steps taken by abalone to make their shells may help materials scientists develop similarly lightweight and effective body armor.

"In our search for a new generation of armors, we have exhausted the conventional possibilities, so we've turned to biology-inspired, or biomimetic, structures," Meyers said. "The laminate structure of abalone shell has stimulated our group to development of a new synthetic material using this lowly mollusk as a guide."

Meyers said a key to the strength of the shell is a positively charged protein adhesive that binds to the negatively charged top and bottom surfaces of the calcium carbonate tiles. The glue is strong enough to hold layers of tiles firmly together, but weak enough to permit the layers to slip apart, absorbing the energy of a heavy blow in the process. Abalones quickly fill in fissures within their shells that form due to impacts, and they also deposit "growth bands" of organic material during seasonal lulls in shell growth. The growth bands further strengthen the shells.

The precise way that building blocks of shells assemble determines their strength, and many of those details have been unknown. "Contrary to what others have thought, the tiles abutting each other in each layer are not glued on their sides, rather they are only glued on the top and bottom, which is why adjacent tiles can separate from one another and slide when a strong force is applied," Meyers said.

Abalone are currently critically endangered in many parts of the world, in fact the only hope for the abalone in certain parts of africa and asia is in the hands of aquaculture institutes and commercial fish farming.

About the Author:

Travis is charge of the sales and online marketing of Camara Consulting, a software development firm, based in Cape Town, South Africa. He also currently does SEO work for Absolute Aquaculture Africa, specialists in african aquaculture.

Article Source: ArticlesBase.com - Bullet Proof Abalone