Sea Shell Armor – Nacre Layer

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Thousands of years ago soldier’s protective armor and shields were sometimes fashioned from tortoise shell. Today, researchers are again turning to shells to inspire a new generation of armaments. I’m Jim Metzner and this is the Pulse of the Planet. Benjamin Bruet is a graduate student in MIT’s Department of Material Science and Engineering.

Our ultimate goal is to design a new battle suit for the soldier. Made of very novel materials. And so, my goal, within this big project is to find a material would be lightweight and very resistant to impact. And our idea is to actually study what nature has done among hard biomaterials, like seashells or, you know, turtle shells, antlers. And so understand how those materials work. And then finally, design materials, synthetic materials based on the structure of those biomaterials.”

Scientists are particularly interested in seashells because of the incredible strength of their nacre layer.

“Nacre is actually the toughest layer that you will find in a seashell. A seashell is composed of different types of layers. The outer layer is one of the hardest, which is about a tenth of an inch thick. Nacre is made of about 95% calcium carbonate. Which really, is limestone. And as you know, calcium carbonate is not a very tough ceramic. But still, the amazing thing with nacre is that if you take a little piece of calcium carbonate and a little bit of seashell of the same dimensions, and you try to break both, you will need 3,000 times more energy to break the nacre piece than to break the calcium carbonate. So and that is really why we are interested in this amazing material.”

We’ll hear more about the structure of nacre and its remarkable durability in future programs. Pulse of the Planet is made possible by the National Science Foundation.

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Sea Shell Armor - Nacre Layer

Scientists are looking to natural structures and materials for inspiration in building the lightweight materials of the future.
Air Date:07/17/2006
Scientist:
Transcript:

music
Thousands of years ago soldier’s protective armor and shields were sometimes fashioned from tortoise shell. Today, researchers are again turning to shells to inspire a new generation of armaments. I’m Jim Metzner and this is the Pulse of the Planet. Benjamin Bruet is a graduate student in MIT’s Department of Material Science and Engineering.

Our ultimate goal is to design a new battle suit for the soldier. Made of very novel materials. And so, my goal, within this big project is to find a material would be lightweight and very resistant to impact. And our idea is to actually study what nature has done among hard biomaterials, like seashells or, you know, turtle shells, antlers. And so understand how those materials work. And then finally, design materials, synthetic materials based on the structure of those biomaterials.”

Scientists are particularly interested in seashells because of the incredible strength of their nacre layer.

“Nacre is actually the toughest layer that you will find in a seashell. A seashell is composed of different types of layers. The outer layer is one of the hardest, which is about a tenth of an inch thick. Nacre is made of about 95% calcium carbonate. Which really, is limestone. And as you know, calcium carbonate is not a very tough ceramic. But still, the amazing thing with nacre is that if you take a little piece of calcium carbonate and a little bit of seashell of the same dimensions, and you try to break both, you will need 3,000 times more energy to break the nacre piece than to break the calcium carbonate. So and that is really why we are interested in this amazing material.”

We’ll hear more about the structure of nacre and its remarkable durability in future programs. Pulse of the Planet is made possible by the National Science Foundation.

music