US Patent 7799196 - Electromagnetic sorting and deposition of nanotubes

http://ip.com/patent/US7799196

This patent from Micron Technology teaches a carbon nanotube deposition method which includes a step of filtering and aligning the nanotubes by size. Claim 1 reads:

1. A method of depositing nanotubes onto a workpiece, comprising:

contacting a surface of a semiconductor wafer with a deposition fluid containing a plurality of nanotubes;

separating a first portion of the nanotubes from a second portion of the nanotubes with a filter located between the contacted surface of the semiconductor wafer and a counter-electrode;

aligning the first portion of the nanotubes relative to the surface of the semiconductor wafer while the first portion of the nanotubes are separated from the second portion of the nanotubes; and

establishing an energy field between the surface of the semiconductor wafer and the counter-electrode in the deposition fluid to deposit the separated and aligned first portion of the nanotubes onto the semiconductor wafer, wherein the energy field is at least one of an electric field and an electromagnetic field.