Numerical Studies of Electrokinetically Controlled Concentration of Diluted DNA Molecules in a T-Shaped Microchannel

Sample concentration is extremely important in microfluidic detection systems, especially for the detection of trace substance. Among various sample concentration techniques used in microfluidic devices, direct electrokinetic trapping is more convenient and easier to realize. In this paper, a T-shaped microchannel configuration was developed to achieve electrokinetic concentration. Numerical simulation analysis on two-dimensional (2D) configuration model were performed. The microfluidic configuration for DNA enrichment was firstly optimized by analyzing various field distributions. Then, the influence of selected dimension and electrical parameters on enrichment rate was analyzed, including size of the transition chamber and enrichment chamber, distance between the inlet branches, length of the inlet vertical branches, size of the electrode and the electric field intensity. With optimized parameters, our model is able to achieve an optimal enrichment rate of 234.2 at an applied voltage of 20 V within a period of 1200s. Our method provides a valuable guidance for the design of an easy-controlled microfluidic system of precise enrichment capability.