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. Published under license by AIP Publishing.