Non-thermal Atmospheric Pressure Plasma Jet for Biomedical Applications

Non-thermal atmospheric pressure plasma jets have been proven to be an excellent source because of their several novel applications. The high electron temperature enhances the plasma chemistry processes while the plasma gas remains close to room temperature. In this work, an atmospheric pressure plasma jet generated in He/oxygen gas mixtures has been investigated. The plasma is generated by an ac voltage with a fixed frequency of 60 kHz. Three important plasma parameters include electron density, electron temperature and gas temperature were estimated using electrical characterization and optical emission spectroscopy diagnostic techniques. Plasma density has been estimated from current measurement and is in order of 10¹³ cm^-3. The gas temperature has been determined by fitting of the experimental spectra and using the Boltzmann plot method. Plasma gas temperature is near room temperature (300 K) in the active zone between the electrodes and was found to increase in the afterglow. The plasma jet shows a non-thermal behavior and is applicable for treatment of polymer and biomedical applications. In the second part of the work, the applications of the plasma jet for the surface treatment of temperature-sensitive materials such as biological polymers and in particular, the interaction of plasma with living cells and bacteria have been examined. Our results show that, non-thermal plasma jet is an efficient source for biomedical applications, where yield of radicals and plume length can be controlled by variation of gas flow rate and discharge parameters.