Plasma-Induced Flow of De-Mineralised Water is Governed by the Aqueous Grounding Configuration

Plasma-induced liquid flow is a topic which is receiving accelerated interest in recent years as a possible method to controlthe distribution of reactive oxygen and nitrogen species through a liquid, thereby improving the efficiency of plasma-liquidinteractions. Here we demonstrate how the induced flow strength can be controlled by tuning the applied voltage of a systeminvolving a monopolar pulsed non-thermal helium atmospheric pressure plasma jet and de-mineralised water. A combination ofexperimental results and scaling laws demonstrate that in electrically floating liquids, the liquid flow is dominated by gas phaseEHD forces, whereas the dominant flow mechanism becomes less clear in electrically grounded liquids. The results of thisstudy therefore clearly show the important role the electrical grounding configuration plays in plasma-induced liquid flow.