Controlled electrocoalescence in microfluidics: Targeting a single lamella

Electrocoalescence of aqueous droplets is investigated as a tool for microfluidic processing. Where droplets are separated by only thin lamellae, coalescence can be induced on demand within a fraction of a millisecond at low potentials (few volts). The authors show that in their approach electrocoalescence proceeds through an electric-field-induced dynamic instability of the oil/water interface. When the electrode geometry and applied potential are optimized, individual lamellae can be targeted for rupture within highly ordered droplet arrangements.