Algorithm Analysis of Gas Bubble Generation in a Microfluidic Device

We investigated the algorithm analysis of the bubble generation in a microfluidic device to study the effect of the surface tension and the flow rate on the microbubble size. For the analysis of the surface tension, five different solutions were used: 3.5% brine, mineral oil, 1% polyethylene glycol (PEG) 400, 1% tween 80, and 1% triton X-100. The various flow rates were also employed: 5∼15 µL/min for the liquid and 100∼200 mL/min for the gas phase. The size of the bubble was measured via the algorithm analysis and the bubble defect was also detected by c chart. We observed that the microbubble size was affected by the flow rates of solution and the gas. Hence, we developed an equation to estimate the size through the flow rate ratio between the solution and gas phase, showing that the microbubble size could be controlled by the liquid properties or the flow rates. Therefore, this algorithm-based microfluidic device could be a powerful tool for generating gas micro-bubbles in a controlled manner.