Active regulation of droplet division in microfluidic chips: multi-physics coupled model prediction and high-throughput experimental validation

The controllable splitting of droplets is vital in the field of microfluidics, playing a crucial role in high-throughput reactions, analyses, and syntheses. In this study, we innovatively construct a microdroplet precision splitting system based on multi-level fluid control, and realize the control of droplet dynamic behavior. Initially, computational fluid dynamics (CFD) simulations are carried out to comprehensively analyze the generation, transportation, and splitting processes of droplets. Subsequently, a series of experiments are executed within the microfluidic systems. We proposed three chip designs with progressive control functions: basic unregulated structure (Chip I), single-channel controlled structure (Chip II), and dual-channel co-regulatory structure (Chip III). The remarkable consistency between the simulation results and experimental data validates the exceptional controllability of microdroplet splitting. This study makes a breakthrough in combining fluid dynamics focusing with active flow control, and establishes a multi-parameter collaborative regulation mechanism for the microdroplet splitting process. Additionally, it validates the effectiveness of our new microfluidic structures in droplet splitting and paves the way for optimizing high-throughput processes in various applications.