US Patent 7220971 - Nanotube field emitters used in biological processing

http://www.freepatentsonline.com/7220971.html

Irradiation of biological cells is used in analyzing the radiation risks in cancer therapy. This patent from the University of North Carolina teaches using nanotubes as electron emitters to provide selective irradiation of cells. Claim 1 reads:

1. A method for selectively irradiating target biological cells, the method comprising: (a) providing a plurality of individually controllable electron field emitters; (b) providing an electrode operable to extract electrons from the electron field emitters; (c) determining target biological cells for irradiation; (d) identifying locations of the determined target biological cells; and (e) individually controlling electron extraction from each of the electron field emitters to selectively irradiate the identified locations for irradiating the determined target biological cells.