LAUSR

Abstract The microfluidic aqueous two-phase system is a new technique that examines the principles of aqueous two-phase systems (ATPS) in micro-dimensions. This system is a suitable platform for the separation and recovery of biological materials in biotechnology. Combining ATPS with microfluidic systems provides features that are impossible or difficult to achieve in macro-scale methods. In this study, it was observed that using multiple interfaces, the rate of separation increases. According to previous studies, ATPS can be considered an inexpensive, environmentally friendly, and effective method for separating biomolecules. Still, its combination with microfluidic systems adds to its attractiveness and efficiency. The studied system with micro-dimensions shows the ability to accelerate the design and optimization of biological processes. A glass microstructure device made with a CO2-laser technique. Various operating parameters, including microchannel length (4–8 cm), salt flow rate (1.6–4 mL/h), and PEG-rich phases (0.8–2 mL/h), were investigated. The response surface method (RSM) was performed to determine the optimal operational parameters. Interphase flow consisted of salt phase and BSA, stabilized between phases, and a parallel flow pattern was obtained. BSA transfer from the salt phase to the PEG phase by the double interface, which increased the BSA recovery rate. Increasing the microchannel length from 4 cm to 8 cm increases the albumin recovery from 41.79% to 71.31%. The studied microfluidic system will increase the recovery rate compared to macro systems with a single interface because of having a double interface.