Thermal disturbance micromixers

Thermal disturbance micromixers rely either on the increase in the diffusion coefficient due to a temperature increase, or on natural convection to enhance the mixing in the microfluidic channel [45, 182]. Recently Kim et al. [182] reported a pumpless micromixer based on thermal disturbance and applied it to perform a polymerase chain reaction (PCR). 

Figure 7.9 Active micromixers (a) serial segmentation (b) pressure disturbance along mixing channel (c) integrated microstirrer in the mixing channel (d) electrohydrodynamic disturbance (e) dielectrophoretic disturbance (f) electrokinetic disturbance in a mixing chamber (g) electrokineticdisturbance in a mixing channel (h) thermal disturbance (i) combination of serial segmentation and focusing.

The term active mixer or active microimxef refers to a microfluidic device in which species mixing is enhanced by the application of some form of external energy disturbance. Typically, this disturbance is generated either by moving components within the micromixer itself, e.g. magnetically-actuated stirrers, or by the application of an external force field, e. g. pressure, ultrasound, acoustic, electrohydrodynamic, electrokinetic, dielectrophoretic, magneto-hydrodynamic, thermal, and so forth [1]. 

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