US Patent 7964174 - Multi-diameter nanotube

http://www.freepatentsonline.com/7964174.html

Carbon nanotubes are usually classified in terms of single walled, double walled, or multiwalled types wherein each nanotube type typically has uniform diameter. This patent from Intel teaches a method of manufacturing an individual nanotube which mixes different diameters and which may play a role in developing nanotube heterojunction electronics. Claim 1 reads:

1. A method, comprising:

forming a first portion of a nanotube with a first diameter;

after forming the first portion, attaching the first portion of a nanotube to a particle; and

after attaching, forming a second portion of the nanotube with a second diameter on the particle coupled to the first portion of the nanotube.