Experimental Study On Microorganism Disinfection And Blood Coagulation Using A Pulsed Cold Plasma Jet

Cold atmospheric plasma jet(CAPJ)is widely employed in many fields such as surface modification and materials processing,wound healing,disinfecting in skin,and so on,due to the active species RONs(Reactive Oxygen Nitrogen species)and low temperature for heat sensitive products.As a novel sterilization technique,CAPJ has attracted a lot of attentions.This paper presents inactivation of microorganism and blood coagulation via a pulsed plasma jet with various inlet gases.The contents and conclusion of this paper are summarized as follow:1.The jet was energized by a pulsed power source with a pulse width of 0.5-3 ?s,a peak voltage of 0-7 kV,and a repetition rate of up to 30 kHz.The jet length changed with inlet gas,and the longest jet length could be longer over 6 cm when using pure He.The plasma jet could treat skin without a sense of overheating and electric shock.2.Adding 6%of N2 or 5%of O2 to pure He or Ar could still produce plasma jet.The temperature of the plasma jet was lower than 40 ?,which was consistent with the low temperature defined in medicine.3.To evaluate the sterilization performance,S.aureus,E.coli and Candida albicans were used as indicator microorganism for experiments.When the plasma jet dealt with agar plates spraying microorganism,it was found that the disinfection area processed by mixed gas was obviously bigger than the other dealt with pure inert gas.The increment of gas addition had benefit to disinfection ability of plasma jet,while the gas had an opposite effect on jet production.The experiments showed the efficacy of S.aureus disinfection could reach up to 99.47%via helium/oxygen(2%)plasma jet.4.The plasma jet could accelerated the surface of blood coagulation,and stimulated the surface of blood sample to form membranous structure.When the volume fraction of helium in the argon helium mixture reached 30%,the jet would cause the surface of blood sample to form a membranous structure with a thickness of 5.5 ?m.In addition to stimulate the cell membrane of the blood platelets,plasma jet could cause the red blood cells to rupture and accumulate.