Now that carbon-fiber composites have migrated from the world of blank-check motorsports to semiaffordable production cars such as the and , what's next? Is there another breakthrough material that will reset our expectations for strength, stiffness, and weight the way carbon fiber has?
Carbon nanotubes will. Imagine a tiny pipe with walls made of carbon atoms linked neatly together. (Shown above: The nanotube's strength stems from the tight bonds joining every carbon atom) The "nano" part of the name comes from nanometer, meaning one-billionth of a meter. Each carbon nanotube is only one nanometer in diameter, which is 2000 times smaller than a carbon-fiber filament. But more significant than size are the dramatic differences in crystal structure and physical properties between carbon nanotubes and carbon fiber. Versus the nanotube's neatly organized, tightly bonded configuration, carbon fiber is what quantum chemists call turbostratic, meaning flat layers, each one a single carbon atom thick, stacked somewhat haphazardly on top of one another. The carbon nanotube's superior atomic-bonded crystal structure is what makes it the strongest, stiffest material known to man and nearly 20 times stronger per pound than carbon fiber.
Nanotubes are grown in furnaces by vaporizing carbon particles with a laser. While this isn't something you can do at home, processes are being developed to commercialize a variety of nano materials. The potential uses are vast. Massachusetts Institute of Technology mechanical engineering professor John Hart predicts that beginning the car-manufacturing process at the nano level will eventually yield lighter bodies, more-efficient catalytic converters, thinner paint, and improved powertrain heat transfer.
in Columbus, Ohio, is a carbon nanotechnology pioneer with more than a decade of experience engineering materials for aerospace, marine, sporting goods, and automotive applications. The firm manufactures , which is carbon fiber reinforced with carbon nanotubes and graphene (a sheet of carbon one atom thick). Zyvex claims that Arovex provides nearly twice the fracture resistance of conventional carbon fiber. Racers use the company's two-part epoxy adhesive enhanced with carbon nanotubes to repair crash-damaged carbon-fiber tubs. Epovex delivers high strength, resistance to peeling, and excellent flexibility.
Just as amazing is Epovex's price, which is roughly $1 per ounce, or about the same as the cost of Super Glue. This does not mean that carbon nanotube–reinforced adhesives are on their way to your local hardware store. Until the health effects of nano materials roaming on and in your body are understood, they'll remain on EPA and OSHA watch lists.