流路急拡大・縮小を活用したマイクロ液滴の合体ディバイスの開発

抄録

Droplet-based microfluidics is expected to be used in various fields such as nuclear energy, chemistry, and medicine. However, it has been difficult to produce stable instantaneous coalescence of multiple droplets in the past. In this study, a flow channel with a diamond-shaped expanded chamber was newly designed to achieve instantaneous coalescence of multiple droplets and to adjust the number of coalescing droplets according to the flow rate conditions. Fluid experiments were conducted using PDMS to create a flow channel. As a result, 2-7 droplets coalescence was successfully achieved with high stability. We confirmed that the desired droplet number coalescence could be easily achieved simply by adjusting the flow rate. Furthermore, analysis of the experimental results to investigate the conditions for the number of droplet coalescences revealed that the motion of the droplets perpendicular to the flow direction is a major contributor to the number of coalescences. CFD simulations were also performed to confirm that droplet coalescence also occurs in the analysis.