Patent ID: 8120889

Claim:
A charging device comprising: a first electrode; a second electrode separated from the first electrode; a plurality of nanostructures contacting at least one of the first electrode and the second electrode; a first voltage supply connected between the first electrode and the second electrode, wherein the first electrode and the second electrode impart charge to a portion of a gaseous material in a charging zone between the first and the second electrode that is deposited on a receptor; a second voltage supply connected between the receptor and one of the first electrode and the second electrode, wherein the second voltage supply is configured to generate an electric field to direct charged gaseous material onto the receptor; and a third voltage supply connected between the receptor and an aperture electrode and arranged to supply a potential difference between the receptor and the aperture electrode to enable a flow of gaseous material to have a velocity below about 100 m/s and a nondimensional space charge density less than about 5, wherein the aperture electrode is arranged between both the first and the second electrode and the receptor and in a flow path of the charged gaseous material.