Number 134 (Story #3), June 24, 1993 by Phillip F. Schewe and Ben Stein SINGLE-LAYER CARBON NANOTUBES have been mass-produced by scientists at IBM-Almaden and NEC Corporation in Japan working independently. Previous methods of mass-producing carbon nanotubes, the all-carbon tubular structures with widths on the nanometer scale, resulted in nanotubes of various sizes, usually having multilayered shells of carbon atoms. However, when metal catalysts (and for the NEC researchers, a methane-argon gas mixture) were added to the graphite electrodes traditionally used to make the nanotubes, batches of uniform thickness resulted. Electron diffraction studies revealed that the nanotubes had widths in the 1 nm range, corresponding to a single-atom thickness. Producing single-layer nanotubes in bulk will allow for better tests of theory. (S. Iijima et al.; D.S. Bethune et al, Nature, 17 June 1993; Science News, 19 June 1993.)