Microfluidic techniques precisely miniaturize macroscale experiments by decreasing volumes of reagents and enhancing spatio-temporal control over reactions. Implementing droplet-based microfluidics enables automation of bioassays with high-throughput analysis and data precision in self-contained miniature reactors. Surfactant-stabilized droplets and their contents can further be manipulated by external physical stimuli in a variety of ways by integrating functional microfluidic units into device construction. For example, implementing electric field generation into microfluidic units enables tasks such as: sorting and selection of specific water-in-oil droplet populations ; releasing droplet content ; initiating reactions by merging droplets with different cargos ; or injecting additional fluids directly into the aqueous phase of the droplets . Apart from sorting in the microfluidic units described above, droplet manipulations including picoinjection may be achieved by electrocoalescence. Specifically, a T-junction microfluidic injection device can be combined with an electric field generating microfluidic unit that induces a thin-film instability at the water-oil interface as droplets pass the orthogonal injection channel. This interface destabilization leads to pore formation in the surfactant membrane and enables picolitre volumes of aqueous reagents from the perpendicular junction to be injected into the aqueous core of passing droplets.