Numerical simulation of micromixing with isolate bubbles in microfluidic flow-focusing devices

Microbubbles play an important role in the micromixing of micro-fluidic systems. However, there are few results in the literature about the mixing of the liquids caused by bubbles flow. The paper presents the numerical simulation of bubbles flow in microfluidic, which agrees well with the experimental results. The influence of velocity amplitude, frequency and phase difference on the mixing performance was investigated. The results show that the isolate bubbles as obstruction can improve mixing efficiency in the true straight microchannel, the bigger the velocity amplitude, and the higher the frequency, the better the mixing efficiency is, but the mixing efficiency has nothing to do with the number of bubbles and just benefit from the certain phase difference. With the other two parameter remains unchanged, the mixing performance achieves the best value when the velocity amplitude is 0.25m/s, the frequency is 25HZ, the phase difference is 0.25 pi, respectively. The study referring to bubbles flow induced mixing performance is very important for many microfluidic devices.