US Patent 7189430 - Simultaneous vertical and horizontal CNT growth

http://www.freepatentsonline.com/7189430.pdf

Fabrication of high density nanotube arrays on a substrate has been achieved by a variety of catalytic growth methods, but most of these methods are constrained to forming vertical arrays. This patent from Rensselaer Polytechnic Institute proposes a method capable of forming both horizontal and vertical nanotube arrays on a substrate simultaneously. Claim 1 reads:

1. A method of making carbon nanotubes, comprising: providing a substrate containing a plurality of oxide template structures having at least a portion covered by a masking material; providing a nanotube source gas onto the plurality of oxide template structures; and selectively growing the carbon nanotubes on an exposed portion of each of the oxide template structures but not on exposed portions of the substrate and not on portions of the oxide template structures covered by the masking material; wherein the step of selectively growing the carbon nanotubes comprises simultaneously growing carbon nanotubes of a different length by providing the nanotube source gas for a sufficient time to allow the carbon nanotubes growing on the exposed portion of each oxide template structure to contact the masking material covering the covered portion of an adjacent template structure.