According to Xiaobao Yang, Yi Ding and Jun Ni from Tsinghua University in Beijing, China, the best configuration for boron is to take the unstable hexagon lattice and add an extra atom to the centre of some of the hexagons (see image, top right). They calculate that this is the most stable known theoretical structure for a boron nanotube.
Their simulation also shows that, with this pattern, boron nanotubes should have variable electrical properties: wider ones would be metallic conductors, but narrower ones should be semiconductors. If so, then boron tubes might be used in nanodevices similar to the diodes and transistors that have already been made from carbon nanotubes, says Ni.
Metallic boron nanotubes would still be useful, however, as they should be better conductors than carbon, and be superconducting at higher temperatures so if a superconducting nanocomputer is ever built, it might have boron wiring.
To actually make the boron tubes, Ni suggests chemical vapour deposition, which is a process already used to grow carbon nanotubes