A Study of Flow Rate Moderation in Microfluidic Devices for Generating Chemical Gradients

We study the effects of changing the input flow rates in simulated microfluidic devices (MFDs) designed for generating different chemical gradients. Our MFD’s input concentrations (0% and 100%) are deployed through microchannels repeatedly assembled into bifurcations, trifurcations, and mixing junctions, ultimately delivering a two-dimensional chemical landscape in a rectangular chamber. Our mixing junctions have different geometries to address the formation of the concentration landscape. Some geometries exhibit a diffusion rate faster than the flow rate, degrading the predicted gradient across the chamber. MFD designs with and without geometric modification are included in the study to determine if the Y-mixer shape influences flow rate moderation. Thus, we evaluate how changing the input flow rates by factors of 0.15, 1, and 1.5 affects the chemical gradient produced in the chamber.