Numerical simulation of electrokinetic flow in microfluidic chips

Abstract

Microfluidic chips are miniaturized analytical devices used in chemical, biological and medical applications. In most cases, fluids are conducted through microchannels by applying electric potentials and/or pressure gradients. This growing lab-on-a-chip technology requires numerical simulations to assist the design, control and optimization of analytical manipulations. The present work deals with FEM-based calculations of the dynamics of electrolyte solutions in cross-shaped microchannels, where the flow is driven by the action of external electric fields. A theoretical modeling of electrokinetic and transport phenomena in the system is carried out in the framework of continuum fluid mechanics. Calculations ground on conservation equations of mass, momentum and electrical charge, considering effects in three dimensions. Operations normally performed in analytical systems are discussed, such as loading, focusing, and injection of samples. Numerical simulations carried out in this work can be a valuable tool to control and optimize practical manipulations in microfluidic chips.