Atmospheric Pressure Plasma Treatment of Surfaces with Obstacles: Controlling RONS and Photon Fluxes

When atmospheric pressure plasmas propagating as bulk ionization waves strike a dielectric surface, charging of the surface produces a local electric field parallel to the surface that enables a surface ionization wave (SIW). A SIW propagating on a flat, smooth surface generally delivers uniform fluxes of radicals, ions and photons to the surface along its path. When obstacles are encountered on the surface (e.g., steps, channels) as might occur during functionalization of complex surfaces, the trajectory of the SIW is perturbed as are the fluxes of reactive species and photons to the surface. In this work, results from a computational investigation of a helium atmospheric pressure plasma jet flowing into air incident onto complex dielectric materials will be discussed. The computations were performed using the plasma hydrodynamics model nonPDPSIM [1]. The distributions of the fluxes and fluences of reactive oxygen and nitrogen species (RONS), ions and photons onto the complex dielectric surfaces will be discussed based on substrate material, dimensions of barriers and applied voltage polarity.

[1] S. A. Norberg et al, Plasma Sources Sci. Technol. 24, 035026 (2015)