Research On The Tissue Penetration Mechanism And The Factors Affecting The Liquid Phase Chemical Reaction Of Atmospheric Pressure Low Temperature Plasma Jet

With the development of low temperature plasma technology,researchers have developed many atmospheric pressure low temperature plasma generating devices.Because of its safe human contact,no burning or electric shock,and the plasma is generated in the open space,which means the plasma is not limited by the size of the space.Therefore,atmospheric pressure plasma jet（APPJs）device has great application prospects in the field of biomedicine.This article explores the reaction mechanism of the atmospheric pressure low temperature plasma jet interacting with the biological liquid environment by using pig muscle tissue of different thickness as a biological tissue model and measuring the reactive species in the 6 different components of the receiving fluid under the muscle tissue that simulate the biological fluid environment.In addition,in order to be closer to the real biological fluid environment,the aquatic reactive species concentration of air APPJs are studied by adjusting the dissolved gas components in the liquid environment.Finally,in order to further explore the control method of APPJs aquatic reactive species,the pulse DC source coupled AC source is used to drive APPJs,and the concentration of reactive species in the liquid phase environment is regulated by adjusting the two power supply coupling methods.Through research,we have obtained the following work.（1）The effects of liquid composition and tissue thickness on the penetration of long-lived nitrogen-oxygen reactive species produced by plasma jets were explored.It was found that as the thickness of this tissue increases,the concentration of reactive species penetrating the tissue decreases,but all can penetrate 500μm thick muscle tissue.The organic component in the solution will increase the concentration of reactive species compared to the inorganic component under the same conditions.At a tissue thickness of 500μm,the concentration of hydrogen peroxide in the receiving fluid of the organic group is higher than that in double-distilled water.The concentration of nitrate and nitrite in the serum receiving solution is much higher than that in several other liquids.（2）By using the laboratory-made DC-driven air plasma array device to treat five kinds of double distilled water containing different gas components（air,airless,nitrogen,oxygen,carbon dioxide）,the concentration of reactive species in the treated solution was measured and systematically analyzed How different dissolved gases affect the concentration of reactive species.The results show that CO₂ itself and the H⁺produced by its dissolution will directly or indirectly affect the formation of various reactive species,and dissolved oxygen will also participate in most chemical reactions as an intermediate or final product of the reaction.Nitrogen can also participate in multiple liquid-phase chemical reactions by producing NO with oxygen.（3）The experiment explored what the operating parameters of the coupled dual power supply on the plasma can influence the concentration of aquatic reactive species.The results show that when the AC source is connected to the needle electrode,the short pulse width（1μs）DC source is connected to the ring electrode,and the DC source lags the AC source by 270°.is conducive to the generation of hydrogen peroxide,hydrogen ions and nitrate ions in the solution;while the AC source is connected to the ring electrode and the DC source is connected to the needle electrode,the DC source lags the AC source by 90°is conducive to the production of nitrite ions.