Experimental and computational study of gas bubble removal in a microfluidic system using nanofibrous membranes

This paper presents a simple and efficient method for removing gas bubbles from a microfluidic system. This bubble removal system uses a T-junction configuration to generate gas bubbles within a water-filled microchannel. The generated bubbles are then transported to a bubble removal region and vented through a hydrophobic nanofibrous membrane. Four different hydrophobic Polytetrafluorethylene membranes with different pore sizes ranging from 0.45 to 3 μm are tested to study the effect of membrane structure on the system performance. The fluidic channel width is 500 μm and channel height ranges from 100 to 300 μm. Additionally, a 3D computational fluid dynamics model is developed to simulate the bubble generation and its removal from a microfluidic system. Computational results are found to be in a good agreement with the experimental data. The effects of various geometrical and flow parameters on bubble removal capability of the system are studied. Furthermore, gas–liquid two-phase flow behaviors for both the complete and partial bubble removal cases are thoroughly investigated. The results indicate that the gas bubble removal rate increases with increasing the pore size and channel height but decreases with increasing the liquid flow rate.