Basic Study on Generation and Sterilization of Sheet Type Plasma Jet-Like DBD under Atmospheric Pressure
T. Kawasaki1, S. Hoketsu1, H. Morisaki1, K. Sato1, H. Baba1, S. Umeda1, Y. Nakagawa1, S. Wakamatsu1, and M. Sakai2
1Department of Mechanical and Electrical Engineering, Nippon Bunri University, Japan
2Department of Media Technologies, Nippon Bunri University, Japan
Abstract- Atmospheric non-thermal plasma has attracted attention of many researchers in the field of environmental and biomedical technologies. In this study, the sterilization effect was investigated using the sheet type plasma jet-like DBD, which was generated between asymmetric electrodes with dielectric plates in helium flow released into the atmospheric air. Helium gas with a flow rate of 2.0 L/min was supplied into the jet-like DBD generator applied a sinusoidal 1 kHz high voltage. Yeast with agar medium in a Petri dish was placed onto the grounded electrode maximum 14 mm away from the tip of the generator. The influence of the applied voltage, irradiation time, electrode size, and distance between yeast and the high voltage electrode on sterilization was investigated in order to obtain the conditions for wide area sterilization. As a result, the clear zone area (mm2) was increased with increasing the applied voltage and irradiation time. On the other hand, it is indicated that there are optimum conditions for the electrode size and irradiation distance from the view point the sterilization efficiency (mm2/W). The jet-like DBD was radially generated in the gap at an irradiation distance of 12 mm and 14 mm when the applied voltage was increased to more than 20 kVp-p.
Keywords- Atmospheric-pressure plasma jet, dielectric barrier discharge (DBD), yeast, sterilization