Geometric flow control in lateral flow assays: Macroscopic single-phase modeling

To describe the dynamics of fluid flow in Lateral Flow Assays (LFAs) and to understand the effect of geometry on the propagation speed of the fluid front, a single-phase model is developed. The model can predict wicking time for different geometries. Axisymmetric geometries with changes in their cross sections are studied to understand the wicking behavior. To validate the modeling results, imaging experiments that capture the fluid front are conducted on all geometries. In all cases, convincing agreement between modeling results and experimental data has been observed. Using data-driven information and knowledge about structure–property correlations, it is possible to control wicking processes to establish a desired velocity at a specific position in LFAs. The proposed approach serves as a basis for the creation of a design tool for application-oriented membranes.