Induced liquid phase flow by RF Ar cold atmospheric pressure plasma jet

The plasma of an atmospheric pressure plasma jet strongly interferes with a liquid when it just touches the liquid surface. The gas flow of the jet exerts a force on the liquid surface pushing it downwards, while the plasma exerts a force which is partly counteracting the gas flow induced force. The downward force in the centre of the liquid recipient causes the liquid to circulate with a circulation time of ~2 sec. Due to this circulation the color change of a dye proceeds homogeneously.