Aqueous medium-induced micropore formation in plasma polymerized polystyrene: an effective route to inhibit bacteria adhesion

International audienc

Time Behaviour of Helium Atmospheric Pressure Plasma Jet Electrical and Optical Parameters

Low temperature plasma jets gained increased interest in the last years as a potential device in many life science applications, including here human or veterinary medicine. Standardisation of plasma sources and biological protocols are necessary for quality assurance reasons, due to the fact that this type of atmospheric pressure plasma source is available in multiple configurations and their operational parameters span also on a broad range of items, such as all characteristics of high voltage pulses used for gas breakdown, geometrical characteristics, gas feed composition and conductive or biological target characteristics. In this paper we present results related to electrical, optical and molecular beam mass spectrometry diagnosis of a helium plasma jet, emphasising the influence of various operational parameters of the high voltage pulses on plasma jet properties. Discussion on physical parameters that influence the biological response is included, together with important results on plasma sources statistical behaviour until reaching a quasi-stationary working regime. The warm-up period of the plasma jet, specific to many other plasma sources, must be precisely known and specified whenever the plasma jets are used as a tool for life science applications

Understanding the evolution of a He and He/O2 capillary plasma jet

In this study, a two-dimensional axi-symmetric model has been developed in order to shed light into the evolution of a He and He/O2 capillary plasma jet. The plasma jet interacts with a dielectric surface placed normal to the jet axis to bring the model closer to applications. This work examines, from first principles, the shape and speed of the of the plasma bullet, the intensity of the induced electric (IEF) field on the dielectric surface and the underlying dominant chemical reactions of the plasma. Furthermore, the work provides insight and understanding into the mechanisms behind many experimental observations such as the torus (or donut) and sphere plasma bullet shapes for pure Helium and He/O2 plasma, respectively