Precise Bacteria Sterilization with Self-Designed Micro Plasma Plume Jet:An Instrumentation Study

A novel type of the plasma generator,capable of producing micro plasma plume jet,was developed to completely deactivate bacteria in a precisely localized area.The self-designed plasma generator comprises:a metal capillary(Φ0.2 mm×800 mm),pulsed high frequency and high voltage power-supply and gas supply with flow-rate regulator.The influence of the plasma generation conditions,including the gas type,voltage and frequency,on the plasma jet length and bacteria sterilization was investigated for design optimization.The results show that the self-developed micro plasma plume jet is capable of completely deactivating bacteria in an area,2 mm in size under the optimized conditions,including the 19 kHz,26 kV pulsed voltage and He(or N₂).When it comes to sterilization mechanisms of E.coli with the plasma-jet in different environment,a descending order exists:H₂O₂/HNO₃ solutions >charged particles ≫ UV-light irradiation> hot air blowing.