Academics, Company Develop High-Performance Nanotech Fiber

Carbon nanotube illustration (National Science Foundation)

Researchers at Northwestern University in Evanston, Illinois and MER Corporation in Tucson, Arizona have engineered a new kind of fiber that can absorb more energy than Kevlar, a fabric now woven into bulletproof vests and other industrial applications. MER — short for Materials and Electrochemical Research — Corporation develops high-tech materials, including those based on nanotechnology.

To create the new fiber, engineering  researchers at Northwestern began with carbon nanotubes — cylindrical-shaped carbon molecules, which individually have one of the highest strengths of any material in nature. When you bundle nanotubes together, however, the tubes start to laterally slip between each other, which reduces their collective strength.

With the help of MER Corporation, the team added added a polymer to the nanotubes to bind them together, and then spun the resulting material into yarns. Then they tested the strength and failure rates of the material. The tests used a powerful microscope to observe the deformation of materials under a scanning electron beam. This new technology provided extremely high resolution images of materials as they deform and fail and allowed researchers to study materials on several different scales. They can examine individual bundles of nanotubes and the fiber as a whole.

The result is a material with a greater ability to absorb energy without breaking, but Kevlar still has a higher resistance to failure. The researchers hope to continue to study ways of engineering the interactions between carbon nanotube bundles and between the nanotubes within the bundle itself.

Team leader and engineering professor Horacio Espinosa secured funding for the research with a grant from the U.S. Army Research Office for the study of disruptive fibers, for eventual use in bulletproof vests, parachutes, or composite materials in vehicles, airplanes and satellites. The U.S. Office of Naval Research also contributed funds for the research.

The findings were published in a recent issue of the journal ACS Nano (paid subscription required).

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