A new high performance fiber that is better at absorbing energy without breaking than Kevlar has been created by the U.S Department of Defence.
While still under development, the material could be used in bulletproof vests, parachutes, or in composite materials for vehicles, airplanes and satellites in the future. The fiber has been engineered from carbon nanotubes spun into a yarn and held together using a polymer. The resultant material is tough and strong while still remaining flexible.
“We want to create new-generation fibers that exhibit both superior strength and toughness,” said Horacio Espinosa, Professor of Mechanical Engineering atNorthwestern University. “A big issue in engineering fibers is that they are either strong or ductile – we want a fiber that is both. The fibers we fabricated show very high ductility and a very high toughness. They can absorb and dissipate large amounts of energy before failure. We also observed that the strength of the material stays very, very high, which has not been shown before. These fibers can be used for a wide variety of defense and aerospace applications.”
The research has been conducted at Northwestern University’s McCormick School of Engineering and Applied Science and is part of the Department of Defense Multidisciplinary University Research Initiative program. Espinosa and his collaborators received $7.5 million in funding to develop the material.
To create the new fiber, researchers began with carbon nanotubes. These cylindrical-shaped carbon molecules are known to individually have one of the highest strengths of any material in nature. Previously the largest issue facing materials researchers has been that when nanotubes are bundled together they lose strength because of lateral slippage. To solve this problem a polymer was added to bind them together, and then the resulting material was spun into yarns.