We find that in the electrolyte, the water contribution to is similar for both negatively and positively charged surfaces, decreasing almost monotonically as the ionic concentration increases. This decrease is explained by the fact that as the concentration of electrolyte ions increases, the amount of water at the interface decreases (see Figure ). At low concentration (1M) the surface tension is fully dominated by the contribution of water (i.e., the value of the solution is almost equal to that attributed exclusively to water; ionic approaches zero), while at higher concentrations, the ionic contribution has a different effect depending on the type of the ion (cations or anions) that is closer to the interface. Interestingly, ionic at the positively charged electrode, is predicted to substantially decrease from 1 M to 2 M, followed by an increase at the highest concentration. A close look in the density profiles calculated for the positively charged surface in Figure , reveals that the thickness of the Helmholtz layer is different among the concentrations studied. In particular, as seen in Table , the OHP exhibits a minimum in the 2 M solution. Notably, this trend closely follows that observed in the dependence of ionic on electrolyte concentration (Figure ). A thicker Helmholtz layer suggests a more diffuse screening of the electrode charge in the immediate vicinity of the electrode, which is expected to upshift the value of ionic (the increased presence of co-ions due to the over-screening effect dampens the repulsive interactions between Cl -that weaken the surface tension.). Furthermore, the significantly higher density of ions inside the Helmholtz The predicted promotion of electrowetting driven by Cl -anions at the positively charged surface is in agreement with the experimental work by Papaderakis et al. , who found that the adsorption of anions (F -) at positively charged surface enhances the electrowetting process. On the contrary, the presence of Li + cations at the interface (i.e. at the negatively charged surface)