Ever since scientists first figured out how to make carbon nanotubes-tiny cylinders of carbon with diameters of a few tens of nanometers-they’ve been touted as the material of the future: as strong as steel but far lighter, with the ability to conduct electricity in useful ways. The problem is that because they’re so small, it’s been difficult to make them at scales that would be useful to industry. You can’t really build a lightweight airplane a few microns at a time, after all.
Now a New Hampshire company, Nanocomp Technologies of Concord, says it has overcome that limitation, producing sheets of carbon nanotubes that measure three feet by six feet and promising slabs 100 square feet in area as soon as this summer.
“From the get-go, we wanted to build something that would be manufacturable,” says Peter Antoinette, CEO and co-founder of Nanocomp. “We’re out to make value-added components out of that material.”
The sheets, which the company can produce on its single machine at a rate of one per day, are composed of a series of nanotubes each about a millimeter long, overlapping each other randomly to form a thin mat. The tensile strength of the mat ranges from 200 to 500 megapascals-a measure of how tough it is to break. A sheet of aluminum of equivalent thickness, for comparison, has a strength of 500 megapascals. If Nanocomp takes further steps to align the nanotubes, the strength jumps to 1,200 megapascals.
The trick, says Antoinette, is being able to make the tubes a millimeter long. Many carbon nanotubes, in addition to having vanishingly tiny diameters, are at best a few tens of microns long (a micron is one-thousandth of a millimeter). So most production processes create what is essentially a powder of nanotubes, Antoinette says.