Synchronized generation and coalescence of largely dissimilar microdroplets governed by pulsating continuous-phase flow.

The effects of pulsating continuous-phase flow on droplet generation at a T-junction are investigated. The pulsating perturbation produced by a microfluidic oscillator is found to govern the droplet formation. In this way, the droplet size, the generation frequency, and the fluid properties become uncorrelated. Within a wide viscosity (1–60 cP) and flow rate range [ Q d , max / Q d , min is on the order of O (10 2) ] of the discrete fluid, the droplet volume increases linearly with Q d and hence can be easily tuned. Using a single perturbation source, microdroplets of largely different viscosities and volumes can be synchronously generated, facilitating subsequent precise control and manipulations such as one-to-one coalescence. [ABSTRACT FROM AUTHOR]