Abstract
A continuous phase liquid and a dispersed phase liquid are permitted to flow together through a co-flow channel. Preferably, the dispersed phase liquid is arranged to flow within the flowing body of the continuous phase liquid in the co-flow channel so that the dispersed phase liquid is sheathed by the continuous phase liquid. The continuous phase and dispersed phase liquids are comminuted into microparticles in the co-flow channel by intermittently blocking the co-flow channel.