A novel microfluidic method to simultaneously measure droplet size and interfacial tension without visualization

Abstract Droplet size and interfacial tension are key parameters related to two‐phase flow. However, current methods for measuring these parameters are usually based on visualization and are therefore not applicable for invisible two‐phase flow systems. Moreover, real‐time determination of interfacial tension is difficult because conventional methods cannot be employed in the flow field. This study presents a novel method for simultaneously measuring the droplet size and real‐time interfacial tension in a two‐phase flow system. A T‐shaped microdevice was designed and integrated with the two‐phase flow equipment. The pressure variation as the droplets flowed through the microdevice was used as a probe to detect the two key parameters, that is, visualization is not required. Monodispersed and multidispersed droplet flows in different equipment were used to verify the method. Both the droplet size distribution and real‐time interfacial tension can be determined using the developed approach.