At a small factory in Concord, New
Hampshire, workers at the startup Nanocomp Technologies are turning
carbon nanotubes into paper-thin sheets many meters long. The nanotubes,
which are each just a few billionths of a meter wide, are among the
strongest and most conductive materials known. For decades researchers
have dreamed of using them to make super-efficient electrical
transmission lines, suspension bridges that can span several kilometers,
and even elevators that convey satellites into space. But while some
companies have succeeded in making useful products by mixing nanotubes
with resins to create composites, it's been difficult to make materials
with properties that reflect those of the individual nanotubes. By
making large sheets composed of nanotubes alone, Nanocomp has taken a
big step in that direction.
The sheets are still not as strong or conductive as individual
nanotubes, but they can provide a lighter replacement for copper and
other conventional materials in some applications, including protective
shielding for coaxial cables. Nanocomp's first customers are NASA, which
has used nanotube sheets to shield a deep-space probe from radiation,
and the U.S. military, which could use the sheets to reduce the weight
of the electrical cables on unmanned drones by half, increasing flight
times.
Nanotubes are made by feeding alcohol and a catalyst into a furnace
at high temperatures and pressures. Nanocomp has fine-tuned the process
to produce relatively long nanotubes that emerge from the furnace to
form networks that can serve as the basis for sheets. Practical
large-scale manufacturing is the critical first step to futuristic
applications, says John Dorr, the company's vice president of business
development. That will get nanotube products out of the lab and to the
market at competitive prices.
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