Modeling Studies of Atmospheric Pressure Microplasmas: Plasma Dynamics, Surface Interaction and Applications.

Abstract

Technologies based on atmospheric-pressure microplasmas (APMs) have been widely developed due to the unique nature microplasmas being non-equilibrium and its ability to operate stably at atmospheric pressure. Electrophotographic printing, sensors, surface functionalization and plasma medicine are typical applications of APMs. However, obtaining accurate measurements and characterizing the plasma parameters are challenging due to the complicated plasma dynamics and the small spatial and temporal scales. In this thesis, results from a computational investigation of APMs are discussed with the goal of improving our fundamental understanding of the nonlinear plasma kinetics of APMs, and to provide design rules for the devices of interest. In this thesis, results will be discussed from a numerical investigation of APMs sustained in dry air in the mDBD arrays, corona discharge and conductive charge rollers (CR) used in electrophotographic (EP) printing technologies, and the charging of both stationary and moving dielectric PC surfaces. The periodic charging patterns predicted by the simulations are consistent with experiment observations. Results will then be presented from numerical investigations of a microdischarge-based pressure sensor sustained in atmospheric-pressure argon. Compared to sensors using piezoresistive and capacitive methods, a microdischarge-based pressure sensor is potentially capable of being an order of magnitude smaller, and more conducive to hostile environments at high temperature.