Droplet-based microfluidics

Droplet-based microfluidics manipulate discrete volumes of fluids in immiscible phases with low Reynolds number (<< 2300) and laminar flow regimes. An early example for using droplet-based microfluidics was a flow-through chip reactor for miniaturized PCR .

Source: Wikipedia — Droplet-based microfluidics (CC BY-SA 4.0)