Generation of Concentration and Temperature Gradients

Concentration gradients can be generated by mixing a solution with a solvent. Mixing dilution between two liquid streams is feasible by controlling their relative EOF speeds [324,436]. 

In addition to the concentration gradient, a temperature gradient has been created on the chip [447]. When the temperature gradient is perpendicular to a 

FIGURE 3.22 General idea of polymer membrane formation at the interface of a two-phase organic/aqueous flow in an X-shaped microchannel layout [435]. Reprinted with permission from the American Chemical Society. 

---