Force fields of charged particles in micro-nanofluidic preconcentration systems

摘要: Electrokinetic concentration devices based on the ion polarization (ICP) phenomenon have drawn much attention due to their simple setup, high enrichment factor, and easy integration with many subsequent processes, such as separation, reaction, extraction etc. Despite significant progress in experimental research, fundamental understanding detailed modeling of preconcentration systems is still lacking. The mechanism electrokinetic trapping charged particles currently limited force balance analysis between electric fluid drag an over-simplified one-dimensional (1D) model, which misses signatures actual system. This letter studies particle phenomena that are not explainable 1D model through calculation two-dimensional (2D) fields. shown significantly distort field flow pattern, turn leads different behaviors sizes. mechanisms behind protrusions instability focused band, important factors determining overall efficiency, revealed analyzing rotating fluxes vicinity ion-selective membrane. differences differently sized understood interplay convective flow. These results provide insights into effect, could facilitate design optimization ICP-based systems.