The Search for a Better Kevlar Norman Wagner of the University of Delaware is working with the U.S. Army on a high-tech fluid that can stop an ice pick and make Kevlar more protective. He tells Renee Montagne about the project.

The Search for a Better Kevlar

The Search for a Better Kevlar

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Norman Wagner of the University of Delaware is working with the U.S. Army on a high-tech fluid that can stop an ice pick and make Kevlar more protective. He tells Renee Montagne about the project.

RENEE MONTAGNE, host:

The Army is using one of those dream materials to make the next generation of body armor. They call it shear thickening fluid. It makes Kevlar more protective and easier to wear. Norman Wagner is working with the Army on the project at the University of Delaware.

Professor NORMAN WAGNER (University of Delaware): The idea here is to be able to reduce the amount of Kevlar required to achieve the same level of performance. The person will have more mobility and be carrying less weight. If you talked to a soldier in the field, what you'll find is they're carrying an enormous amount of weight.

MONTAGNE: Now I want to hear a vivid description of how this liquid...

Prof. WAGNER: Sure.

MONTAGNE: ...ends up being body armor.

Prof. WAGNER: The material really solidifies upon impact, so for example, if you take an ice pick and you try to stab through the fluid, if you go slowly, you can push it through the fluid very easily. But if you stab quickly, suddenly the fluid resists the pick going through it. Similarly, when we combine this fluid with the Kevlar, we're able to work synergistically with the material like Kevlar to prevent the projectile or the ice pick from finding its way through the fabric and penetrating through it. So although this is a fluid, we're not applying it like a sunscreen or something. We're engineering it into the fabrics to get the best of both materials.

MONTAGNE: Is there a small experiment one can do at home to give you the idea of what this more exotic material does?

Prof. WAGNER: If you take some corn starch in powdered form and add a small amount of water, you'll find you can stir it, but if you try to stir it too quickly, it gets very thick and molasseslike. This is a similar phenomenon. Of course, the materials we have are much stronger and much finer particles, but the corn starch-water is a good example of what shear thickening is.

MONTAGNE: What about fire or chemicals?

Prof. WAGNER: We're very interested in applications such as for bomb blasts or IED protection as well as for civilian use by firemen and others who are quite hopeful that we can engineer an additional functionality into the materials to be effective there.

MONTAGNE: But so far this material isn't that ultimate futuristic dream material that can protect one against every possible danger?

Prof. WAGNER: One would like to have the ultimate material that does everything, but certainly we've demonstrated something new and exciting, and I think we're only at the early stages of learning how to best exploit these properties and use them in a deployable device for use in the military or by civilians.

MONTAGNE: Professor Wagner, thanks very much.

Prof. WAGNER: Thank you very much.

MONTAGNE: Norman Wagner is a professor of chemical engineering at the University of Delaware.

STEVE INSKEEP (Host): Let's go back one more time to the main story we've been following this morning: Hurricane Katrina, which plowed into the Louisiana coast today. It's been passing over the city of New Orleans where it has swamped houses in low-lying areas. Much of the city is low lying, of course. We also have reports that buildings have collapsed. Katrina has now been downgraded to a Category 3 storm, but it is still expected to cause a 15-foot storm surge that could flood the city. And, of course, as the worst of the storm misses New Orleans, it's hitting other areas. So NPR will continue its coverage of Katrina throughout this day. And you can follow the path of the storm by going to our Web site, npr.org

This is MORNING EDITION from NPR News. I'm Steve Inskeep.

MONTAGNE: And I'm Renee Montagne.

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