US Patent 7404698 - Vacuum pump with CNT charge source for de-ionization

http://www.freepatentsonline.com/7404698.html

Turbomolecular pumps are used to create high vacuums but can be subject to charge accumulation that can deteriorate operation. This patent from Edwards Vacuum teaches using carbon nanotube as a charge particle source for charge neutralization. Claim 1 reads:

1. A turbo-molecular vacuum exhaust pump, comprising:

a pump housing;

a turbo-molecular pump rotor mounted for rotation in the housing;

an insulating bearing system that supports the rotor for rotation and electrically insulates the rotor from the housing; and

a charged particle source for providing charged particles that interact with the rotor, thereby reducing a static electrical charge of the rotor and wherein the charged particle source is a carbon nanotube.