Experiments on traveling-wave electroosmosis: effect of electrolyte conductivity

Net flow of electrolyte induced by Pt microelectrodes subjected to traveling-wave potentials is studied experimentally. Three different concentrations of KCl in water are considered in order to determine the effect of the electrolyte conductivity on the induced velocity. This work intends to generate more experimental data that can be compared to theoretical models. The experiments at low voltages show that the induced velocity decreases with electrolyte conductivity while the characteristic frequency increases, as theoretically expected. Previous experiments showed that the net flow is reversed for voltage amplitudes above a threshold. In the present work, the threshold voltage for the different electrolyte conductivities is also reported and is found to increase with electrolyte conductivity.