Fibers are spun from a supported array of nanotubes. Fibers are spun using a spinning shaft with, for example, a hook shaped end that contacts the supported nanotubes and twists some of them around each other to begin the fiber. As the twisted nanotubes detach from the support, the shaft moves away from and along the supported array in a controlled direction and at a controlled speed as it spins to twist and detach additional nanotubes from the support and extend the length of the fiber. If the array is pretreated with a dilute polymer solution, excess solution is squeezed out of the growing fiber during spinning, and the polymer may be cured at elevated temperature to provide a strong nanotube composite fiber.
STATEMENT REGARDING FEDERAL RIGHTS
 This invention was made with government support under Contract No. W-7405-ENG-36 awarded by the U.S. Department of Energy. The government has certain rights in the invention.