Capillary filling in centrifugally actuated microfluidic devices with dynamically evolving contact line motion

Abstract

In the present work, we analyze the capillary filling dynamics in centrifugally actuated microfluidic platforms with dynamically evolving contact line motion for wetting fluids. Special attention is devoted to estimate the effects of variable hydraulic resistances over different flow regimes. Dynamics of the meniscus advancement within the rotating microchannel turns out to be typically nonlinear, in tune with the relative instantaneous strengths of the capillary forces, centrifugal forces, and viscous resistances. Detailed dynamical characteristics of the meniscus evolution are obtained from the approximate semianalytical and full-scale numerical solutions, and are found to agree well with the experimental findings on lab-on-a-compact disk arrangements.