Controlled chemical gradients can be produced in a microfluidic chamber using a serial split-and-recombine flow approach with two input concentrations. We investigated the formation of a 2D concentration landscape created by a biased Y-mixer, part of a microfluidic gradient generator. Our study focused on flow rates comparable to interstitial flow in tissues to examine cancer cell migration associated with tumor metastasis. We analyzed the concentration profile along (3.5 mm) and across (0.5 mm) the microfluidic gradient chamber using epifluorescence microscopy and fluorescein sodium salt as a concentration marker. We tracked the flow using 3.5-µm diameter polystyrene particles. Our experimental results align with the empirical model needed for designing these microfluidic structures.
