US Patent 7357690 - Alignment of CNTs using grooves

http://www.freepatentsonline.com/7357690.html

This patent from Canon (priority Nov. 19, 2003) teaches an alignment method of carbon nanotubes or other high aspect ratio structures using a grooved substrate. Claim 1 reads:

1. A method for aligning needle-like structures, comprising: a providing step of providing a substrate having a surface and at least one groove defined therein; and an alignment step of placing the needle-like structures dispersed in a disperse medium in the groove so that the needle-like structures align along a length of the groove in parallel with the surface of the substrate.

However, some prior art may have been overlooked such as US Patent 6,872,645 (see for example column 16, lines 20-56) with priority going back to Sept. 10, 2002.