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The controlling parameters and processes for nanotube regrowth in relation to the synthesis of sharply bent carbon nanotubes are investigated. It is concluded that the regrowth of carbon nanotubes (CNTs) is strongly related to the carbon capping present on the catalyst particle.

Top ends of aligned carbon nanotubes were opened via room-temperature sputter etching of the nanotubes in the same chemical-vapor deposition (CVD) chamber that the nanotubes were grown. The mechanism of the sputter etching process involves incident positive ions in the plasma, such as hydrogen or argon, colliding with the nanotube material and preferentially eroding the nanotube walls around the catalyst metal particles. The cut-off nanotube segments are removed from the sample in the CVD chamber together with the catalyst particles. This process is entirely physical in nature with no wet chemical processing steps involved. The sputter etching process is found to be faster with larger ion size, higher applied voltage forming the plasma, and higher pressure of the sputtering gas. [ABSTRACT FROM AUTHOR]

Presents the responses of several "JOM" journal readers if they were assigned to project manage either the construction of a Death Star or light saber of the "Star Wars" films. Elizabeth Holm of the Sandia National Laboratories; James C. Foley of the Los Alamos National Laboratory; Michael Vinarcik of Ford Motor Co.

A novel multi-branching carbon nanotube (CNT) structure is synthesized by direct current plasma enhanced chemical vapor deposition. The structure consists of aligned CNTs which have branches of smaller diameters growing aligned along a direction perpendicular to the original CNT. The mechanism of branching is explained in terms of a self-seeding of Ni catalyst which is transferred by sputtering from the original catalyst particles in the backbone CNTs to the walls of those CNTs. It is also shown that the branching induced a large increase in surface area and total nanotube length and can be beneficial in supporting very fine Pt nanoparticles for fuel cell and other catalytic applications. Such an array of Y-junction nanostructures could be useful for the fabrication of a high-density array of nanoelectronics switches and transistors.