Abstract
Droplet microfluidics has found diverse applications in the manipulation, detection and synthesis of biological and chemical objects. Generating droplets by using air sheath flow is especially advantageous to further reduce contamination and facilitate evaporation. We have developed a microfluidic droplet shooter capable of injecting samples to the mass spectrometer (MS) at ~100% efficiency. The generation of droplets is due to the air drag force and instability of the gas-liquid interface. Herein, numerical simulation is established to delineate the complex flow fields and fluid-surface interactions inside the shooter. The numerical and experimental results agree well, providing insights for developing droplet microfluidics.