Friday, December 22, 2006

US Patent 7150865 - Semiconductor Nanotube Enhancement Using Microwaves

http://www.freepatentsonline.com/7150865.pdf

Several techniques have been proposed to seperate semiconducting from metallic nanotubes. The approach of this patent takes advantage of the sensitivity of metallic nanotubes to microwaves to damage or destroy the metallic type and leave the semiconducting type. Claim 1 reads:

1. A method for processing carbon nanotubes comprising: receiving a carbon nanotube sample composed of metallic-type and semiconducting-type nanotubes; positioning said carbon nanotube sample in a microwave cavity at a location corresponding to a maximum in the electric field of a stationary wave having a first microwave frequency; and exposing said carbon nanotube sample to a stationary wave having said first microwave frequency and a first power, wherein proportion of semiconducting-type carbon nanotubes in the sample is increased.