Abstract Locally constrictive microchannels are effective components to implement droplet break-up in microfluidic processes. We herein report an experimental study of droplet break-up flow based on pressure drop analysis. The time varying pressure drops were recorded by a self-assembled experimental platform with measurement accuracy of 1 Pa, and the variations of those pressure drops were in accord with the fluctuations of capillary pressure. Fourier transform was then employed to analyze the droplet break-up behaviors and confirm the numbers of daughter droplets instead of traditional microscopic imaging method. With the guidance of the pressure drop analysis, the effects of crucial factors such as surfactant concentration, fluid flow rate, and fluid viscosity on droplet break-up were investigated. The additional hydrostatic energy cost for droplet stretching and deformation in the constriction was finally discussed in contrast to the increase of interfacial energy, which were both confirmed on the level of 10-8 J/droplet.

中文翻译：

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局部收缩微通道中液滴破碎流的压降分析

摘要 局部收缩微通道是在微流体过程中实现液滴破碎的有效组件。我们在此报告了基于压降分析的液滴破碎流的实验研究。时变压降由自组装实验平台记录，测量精度为1 Pa，这些压降的变化与毛细管压力的波动一致。然后采用傅里叶变换来分析液滴的破碎行为并确认子液滴的数量，而不是传统的显微成像方法。在压降分析的指导下，研究了表面活性剂浓度、流体流速和流体粘度等关键因素对液滴破裂的影响。