Optimal Power of Atmospheric Pressure Plasma Jet with a Simple DBD Configuration for Biological Application

Abstract

The new strategy, non-thermal atmospheric pressure plasma (N-APP), as a ’physical’ method, could offer a simple, fast, effective, and economic way of disinfection of equipment, surfaces, a method that is unlikely to cause micro-organisms resistance, or allergic, and toxic reactions. Recently, cold physical plasma had been extensively studied by researchers as a possible therapy in dentistry and oncology, as well as the application of non-thermal plasma in biomedical researches such as wound healing. In clinical dermatology, cold plasmas are mainly used for the treatment of chronic wounds and pathogen-based skin diseases, in which stimulation of tissue repair and decontamination. In this research, the characterization of home-made Helium Non-Equilibrium atmospheric pressure plasma jet (He -NAPPJ), that had been generated using a dielectric barrier discharge (DBD) configuration for exceptional standardization protocol of this plasma source that meets medical requirements. The device equipped with two powered electrodes as well as a grounded electrode, driven by an (8 kVp-p) voltage, the frequency (12 kHz), and the distance between the nozzle of the plasma jet and the target were used as constant data. As a working gas, the Helium gas (He) was used in different flow rates (2, 4, 6, and 8) slm. The optical emission spectroscopy was used to measure the plasma parameters, of which the electronic excitation temperature and density of electrons were determined by the Boltzmann’s plot method and Stark broadening effect equation respectively. The result of the emission line spectrum showed the presence of nitrogen and oxygen between lines 300 nm until 700 nm. Nitrogen and oxygen are involved in the oxidation process which is known as Reactive Nitrogen species and reactive oxygen species. These species are the main key in bacteria inactivation and the wound healing process. Furthermore, the results had revealed, the optimal condition using the flow rate (6 slm) with 32 °C He gas temperature that had been stabilized for 20 min, plume length 40 mm, The distance is 15 mm from the distal end of the Pyrex tube (DBD) and the wound surface, the power density 44 mWatt/cm2, and plasma radiation energy dose: 76 J/cm2. These results were considered in this study as a safe operating condition for biomedical applications.