A Numerical Study of Biomolecule Preconcentration Utilizing ion Concentration Polarization in the H-Shaped Microchannels

Microfluidic devices employ the ion concentration polarization (ICP) phenomenon to preconcentrate very dilute biomolecule samples. Although they have been widely utilized in practice, it is still necessary to understand comprehensively the ICP phenomenon and the preconcentration mechanism. In this work, we propose a 2-D model of the H-shaped microchannels and present simulation results which were obtained by numerically solving four coupled governing equations: Nernst-Planck, Poisson, Navier-Stokes, and electrophoretic equation. By considering biomolecules as particles, we systematically study the effect of important working parameters, including electric potentials, ionic strengths of buffer solution, and dimensions of ion-selective membrane on the preconcentration of biomolecules. These detailed simulation results are useful in understanding the ICP phenomenon and preconcentration mechanism to develop better and optimize micro fluidic concentration devices.