Monodispersed microbubbles and microdroplets are widely used as reaction carriers in microfluidics. In this study, the generation processes of bubbles and droplets in a step-emulsification microfluidic device are compared to show the similarities and differences in the emulsification process. By changing the placement of the microdevice, the effects of buoyancy and gravity on the generation of bubbles and droplets are introduced, and the feedback mechanism of the bubble layer and the effect of droplet accumulation on the emulsification process are clarified. Finally, based on the analysis of the difference of the pinch-off of the dispersed phase between the bubble and the droplet in this configuration, the Plateau-Rayleigh instability processes for the formation of bubble and droplet are revealed by using a high-speed camera system, and the reasons for the difference of the operating ranges of the gas flow rate and liquid flow rate in the dripping flow regime are explained.

单分散的微泡和微滴被广泛用作微流体中的反应载体。在这项研究中，比较了步进乳化微流体装置中气泡和液滴的产生过程，以显示乳化过程中的异同。通过改变微器件的摆放位置，介绍了浮力和重力对气泡和液滴产生的影响，阐明了气泡层的反馈机制和液滴积累对乳化过程的影响。最后，在分析该构型中气泡和液滴分散相夹断的差异的基础上，利用高速相机揭示了气泡和液滴形成的Plateau-Rayleigh不稳定过程。系统，