Multiphase flow in microfluidic systems – Control and applications of droplets and interfaces

Micro- and nanotechnology can provide us with many tools for the production, study and detection of colloidal and interfacial systems. In multiphase flow in micro- and nanochannels several immiscible fluids will be separated from each other by flexible fluidic interfaces. The multiphase coexistence and the small-volume confinement provide many attractive characteristics. Multiphase flow in microfluidic systems shows a complicated behavior but has many practical uses compared to a single-phase flow. In this paper, we discuss the methods of controlling multiphase flow to generate either micro- or nano-droplets (or bubbles) or stable stratified interfaces between fluidic phases. Furthermore, applications of the droplets and interfaces in microchannels are summarized.