US Patent 7109515 - Conical Carbon Nanotips

http://www.freepatentsonline.com/7109515.pdf

Nanoscale tips are very useful to a wide range of applications including biological probes and electron emission devices used in flat panel displays. However, usually the tips are cylindrical in shape and are subject to some vibrational effects. This patent teaches a method to alleviate this problem by forming a conical rather than a cylindrical carbon nanostructure. Claim 1 reads:


1. An apparatus, comprising an expanded base carbon containing tip including: a carbon containing expanded base coupled to a substrate; and a carbon containing extension coupled to said carbon containing expanded base, wherein said carbon containing expanded base is substantially cylindrically symmetrical and said carbon containing extension is substantially cylindrically symmetrical, and wherein the expanded base carbon containing tip defines a slope with a discontinuity between the carbon containing expanded base and the carbon containing extension.