Separation of immiscible liquids using microfluidics

In this study, the continuous separation of hexane and water in micro-systems was investigated. For this purpose, two dimensional glass microfluidic chips were fabricated using laser ablation and thermal bonding method. The chips comprised of a main microchannel and few lateral micro channels. It was aimed to exit hexane and water from the, respectively, main and lateral micro channels. It was found that decreasing the width and increasing the number of the lateral micro channels, and increasing the flow rate of water result in increased separation. Also, increasing the flow rate of hexane and increasing the length of the lateral micro channels result in the reduction of the separation. In order to increase the operating flow rate of the capillary separation, three-dimensional microfluidic chips were fabricated by parallelization of four microscale capillary separators. With the three-dimensional microfluidic chips, the separation efficiency of up to 60% was achieved at the operating flow rate of 1.5 mL min-1.