Resonant Nanopumping in Cylindrical Nanopores with Symmetry-Broken Gate Electrodes

Gate electrodes in electrolyte-filled nanopores enable the precise control of transport processes for applications like DNA translocation or ionic current rectification. Recently, we demonstrated that applying unbiased ac voltages to conical, gated nanopores causes directional flows at intermediate frequencies, a phenomenon called resonant nanopumping. Here, we show the results of numerical simulations of the fully coupled Poisson-Nernst-Planck and Navier-Stokes equations in cylindrical nanopores with ac gate potentials. We show that breaking the symmetry with gate electrodes that partially cover the pore wall can substantially increase flow rates compared to conical pores. We identify the inherent timescales causing the resonance and formulate an analytical model that predicts the flow rates and the resonant dynamic behavior in accordance with our detailed simulations. Our results enable the efficient design and optimization of cylindrical resonant nanopumps, which, compared to conical designs, bear the potential of higher flow rates and simpler manufacturing for future experimental studies.