Low voltage plug flow pumping using anisotropic electrode arrays

Arrays of asymmetric interdigitated electrodes were used to produce fluid flow of an ionic solution. The electrodes were made of transparent (transmission ∼80%) indium tin oxide (ITO) and were powered by AC voltages of less than 5 Vrms. We experimentally confirm predictions that the velocity of the fluid increases with the decreasing dimensions of the electrodes and we achieved velocities in excess of 450 μm/s at 2.2 Vrms. Plug flow for the different electrode dimensions was obtained by placing one array at the bottom of a solution and the other at the top, leaving a gap of 280 μm. The experimental observations fit well with theory.