US Patent 7504628 - Nanoscale corona discharge electrode

http://www.freepatentsonline.com/7504628.html

Corona discharge is an electrical discharge effect used in applications such as air purification and laser printing. This patent teaches the use of conductive nanostructures to enhance the corona effect and increase the efficiency of ionization. Claim 1 reads:

1. A corona discharge electrode comprising:

a conductive support adapted to be exposed to air and to receive an electrical voltage;

a plurality of conductive nanostructures attached to and in electrical communication with the conductive support, wherein the nanostructures have a side attached to the conductive support;

the nanostructures arranged to provide electrodes extending into surrounding air and having radii less than 100 nm to ionize the air at the nanostructure with the electrical voltage.