Title :
DC powered atmospheric pressure micro-plasmajet for biomedical applications
Author :
Kolb, Juergen F. ; Price, Robert O. ; Mohamed, Abdel-Aleam H. ; Schoenbach, Karl H.
Author_Institution :
Frank Reidy Res. Center for Bioelectrics, Old Dominion Univ., Norfolk, VA
Abstract :
Summary form only given. Nonthermal (cold) plasmas operated in air at atmospheric pressure offer an appealing method for the processing and decontamination of surfaces. Most existing devices are operated with radiofrequency high voltages. Microhollow cathode discharges (MHCDs), on the other hand, allow us to generate a direct current driven plasma jet in atmospheric pressure gases, including air. The discharge is sustained by a voltage of only several hundred volts applied to two plane metal electrodes which are separated by a dielectric insulator. The plasma is confined in a cylindrical channel drilled through all layers. With a thickness of the dielectric of 0.25 mm and a diameter of the channel of less than 1 mm a stable glow discharge can be sustained. By flowing air or nitrogen through the channel into atmospheric pressure air, a well-defined plasma (afterglow) jet is generated with a typical, visible length of 10-20 mm. The gas temperature of air and nitrogen plasmas inside the channel was measured by means of emission spectroscopy using the 0-0 band within the second positive system of nitrogen. Increasing the flow rate from 0 to 200 ml/min resulted in a decrease in gas temperature from 2000 K to 800 K in the channel. The lower temperature allows us to replace high temperature ceramics and metals, such as alumina and molybdenum, respectively, with less expensive and easier machinable materials. The turbulent gas flow effectively cools the plasma jet down further to temperatures close to room temperature at a distance of 5 mm from the nozzle. This allows using this micro-plasma jet for treatment of heat sensitive materials and surfaces. E.g., the wettability of polypropylene (melting point 170degC) was increased by 70% when treated with the plasma jet. Other applications include the gentle cleaning and decontamination of organic materials. Studies on the treatment of fungal, viral, and bacterial skin diseases with the plasma jet are underway
Keywords :
afterglows; alumina; ceramics; glow discharges; molybdenum; nitrogen; plasma diagnostics; plasma jets; plasma materials processing; plasma sources; plasma temperature; polymers; surface treatment; wetting; 0.25 mm; 10 to 20 mm; 2000 to 800 K; 5 mm; Al2O3; Mo; N2; afterglow; atmospheric pressure microplasma jet; bacterial skin diseases; biomedical applications; dielectric insulator; emission spectroscopy; fungal skin diseases; gas temperature; glow discharge; heat sensitive materials; high temperature ceramics; melting point; microhollow cathode discharges; nonthermal cold plasmas; organic materials; plane metal electrodes; polypropylene wettability; radiofrequency high voltages; second positive system; surface decontamination; turbulent gas flow; viral skin diseases; Atmospheric-pressure plasmas; Decontamination; Nitrogen; Plasma applications; Plasma confinement; Plasma devices; Plasma materials processing; Plasma measurements; Plasma stability; Plasma temperature;
Conference_Titel :
Plasma Science, 2006. ICOPS 2006. IEEE Conference Record - Abstracts. The 33rd IEEE International Conference on
Conference_Location :
Traverse City, MI
Print_ISBN :
1-4244-0125-9
DOI :
10.1109/PLASMA.2006.1707234
