A cold micro plasma jet device suitable for bio-medical applications

This paper presents a cold plasma jet operating at 20 kHz AC under atmospheric pressure. The micro plasma jet nozzle has a porous alumina dielectric installed between the outer anode and the inner hollow cathode. While nitrogen gas is injected through the hollow cathode and the porous dielectric, an electrical discharge occurs when an AC voltage is applied. This discharge produces a micro plasma jet that is ejected from the micro holes of the anode. The plasma jet device is operated at room temperature. The surfaces exposed to the plasma are modified to hydrophilic ones and the surface temperature increases by less than 5 degrees in 20 s. This non-thermal characteristic confirms the feasibility of the plasma jet device for bio-medical applications. (C) 2009 Elsevier B.V. All rights reserved.