Thursday, December 14, 2006

US Patent 7147831 - Bending Nanotube Array

Growth of vertically oriented nanotube arrays is often performed using a catalytic layer formed on a substrate. However, in order to form more complex structures it would be useful to have the nanotubes formed horizontally or at an angle to the substrate surface so that the nanotubes could be connected at two rather than just one end. This patent is based on collaborative work between a Chinese university and a Taiwanese company and proposes the use of a nonuniform catalytic film so as to create a bending array of nanotubes. Claim 1 reads:

1. An apparatus comprising: a substrate; a catalyst layer disposed on the substrate, the catalyst layer comprising a plurality of nano-sized catalyst particles, sizes of the catalyst particles decreasing along a given direction; and an array of aligned carbon nanotubes extending from the catalyst layer in an arc toward the given direction, a respective length of each carbon nanotube being in proportion to the size of the catalyst particle from which such a nanotube is grown.