US Patent 7749477 - Tracking CNT growth

http://www.freepatentsonline.com/7749477.html

In CVD growth of carbon nanotube arrays the nanotubes usually grow from catalytic particles in a root-growth or a tip-growth fashion. During root-growth the catalyst remains on the substrate while during tip growth the catalyst particle remains on the tip of the nanotube during growth. In order to study these different growth modes and other aspects of nanotube formation researchers at Hon Hai Precision and Tsinghua University have implements an intermittent CVD method in which line markings form on the nanotubes to track their growth. Claim 1 reads:

1. A carbon nanotube array comprising:

a plurality of carbon nanotubes; and

at least one line mark formed on the carbon nanotubes, the at least one line mark transversely extending across the carbon nanotubes;

wherein the at least one line mark comprises a plurality of line marks transversely extending across the carbon nanotubes;

wherein the line marks are parallel to each other; and

wherein the line marks are nonuniformly-spaced.