Micromixer Based Liquid/Liquid Dispersion

Droplet formation of various liquid/liquid systems is investigated in an interdigital micromixer made of glass. By means of the interdigital channel configuration, cylindrically shaped or lamellae‐like substreams of the dispersed phase are generated inside a continuous phase. Using the model emulsion silicon oil/water, the Rayleigh plateau instability is identified as the decay mechanism for cylindrically shaped substreams of the dispersed phase. In comparison, it is suggested by the droplet size distribution of various mixers as a function of the total flow rate that in mixers with more complex fluid‐guiding geometries droplet formation is mainly affected by shear and vortex flows. Shear forces are typically used for droplet breakup during emulsion formation. The required energy is introduced mechanically by ultrasound or by means of shear flows. Besides shear forces, also hydrodynamic instabilities, can be used for droplet formation at the microfluidic level. Droplet formation of various liquid/liquid systems is investigated in an interdigital glass micromixer. An example of a liquid/liquid reaction outlines the benefit of additional shear forces in the interdigital micromixer.