Microfluidic micro mixers apply different mixing principles. They include mixers applying passive and active mixing principles. Passive mixing elements with elongated channels to enforce diffusion mixing or the so-called “herringbone” mixing structures are available. Active mixers with integrated stir bars give the option to generate mixtures with a wider range of mixing ratios, e.g. coping with 1:10 mixing ratios what is not feasible with the passively working devices.

Passive mixers mix liquids by diffusion. As flows in microchannels are normally laminar, the task of these mixers lies in the improvement of the diffusion condition, e.g. by allowing a long co-flow of the liquids or by adding structures to increase lateral velocity. As there are multiple mixing structures on each chip, these can be daisy-chained to improve the mixing result.

This mixer is based on the principle as described in: A.D. Stroock et al., Chaotic Mixer for Microchannels, Science, 295, 647-651, 2002.

The Herringbone Mixer – Channel variation Fluidic 1460 has four functional mixing units, two of which are identical. The chip can be used as a mixer chip, but also for the synthesis of lipid nanoparticles.

This mixer is based on the principle as described in: S. Hakenberg et al., A phaseguided passive batch microfluidic mixing chamber for isothermal amplification, Lab Chip, 12, 4576-4580, 2012.