US Patent 7238952 - Carbon nanotube for metal ion emission

http://www.freepatentsonline.com/7238952.html

The use of carbon nanotube materials for electron emission has been proposed for numerous applications including flat panel displays, lighting, and microwave amplifiers. This patent from Canon teaches how to use carbon nanotubes for ion emission as well which may have some applications in mass spectroscopy and focused ion beam devices. Claim 1 reads:

1. A metal ion emission device for emitting a metal ion by applying voltage to a molten liquid metal, comprising: a needle-like part having an internal opening in which a liquid metal can be moved, and the needle-like part is a carbon nanotube and has a first opening for supplying the liquid metal to the internal opening and a second opening for emitting the liquid metal as a metal ion.