Monodisperse Double Emulsions Generated by Microfluidic Chips Utilizing Flow Focusing and Pneumatic Chopping Devices

This paper reports a new microfluidic chip capable of formation of double microdroplets in liquids for emulsification applications. By combining the flow focusing and pneumatic chopping mechanisms, the proposed device can successfully generate water-in-oil-in-water droplets. When compared with other existing methods for double emulsions, this device has an advantage to actively control the droplets formation by the frequency and pressure of the integrated chopper, indicating that W/O/W droplets can be developed in a controllable way.