Characterization of the pressure-driven flows for droplet microfluidics

摘要

The pressure-driven device is designed to control the flow rates of the droplet microfluidic systems, which can eliminate the flow-rate fluctuations coming from the pump source. As monodisperse droplets are formed in the microchannel, periodic pressure fluctuations can be induced by the dynamic process of droplet formation, which can influence the stability and control precision of the pressure-driven flows. The effects of the pressure fluctuations induced by the droplet formation process on the dynamic characteristics of the open-loop and closed-loop control pressure-driven flows are comparatively studied. Particularly, a PI controller is integrated with the closed-loop system and by properly choosing the parameters of the PI controller, the amplitude of the pressure fluctuations of the pressure-driven flows can be reduced drastically, which can increase the control accuracy of the driven pressure. Additionally, the effects of the container volume on the dynamic characteristics of the pressure-driven flows are also discussed. Most importantly, the study of the pressure-driven flows can be applied for the flow-rate control of the fuel supply system of the aircrafts, and especially, steady supply of the fuel flow rates can be achieved for the aircrafts by the pressure-driven flows.