Exploring the connection between non-uniform electrostatic fields generated by opposite polarity voltages and the behavior of atmospheric pressure plasma jet

This study investigates the counterintuitive behaviors of a microwave-induced atmospheric pressure plasma jet (APPJ) under the influence of an external electrostatic field applied by one or a pair of parallel electrode plates subjected to DC voltages. The findings demonstrate that the plasma jet consistently deflects toward the electrode plate with an electrostatic potential, irrespective of the direction of the applied field. The deflection becomes more pronounced with increasing voltage on the electrode plate until the ionic wind generated by the high voltage significantly affects the jet's behavior. Remarkably, a negative voltage induces a greater deflection compared to a positive voltage. To further investigate this discovery, the dielectric properties and the non-neutral characteristics of the APPJ are analyzed, and the simulations of the electric field distribution reveal a non-uniform distribution, which plays a crucial role in understanding the mechanism behind the observed behaviors of the plasma jet. This study provides a comprehensive understanding of the underlying mechanism driving the observed phenomena and sheds light on the collective behavior of plasma jets under non-uniform electric fields. The findings of this study offer valuable guidelines for investigating and controlling the behavior of APPJs.