A Numerical Investigation on Micro Particle Dynamics Near an Evaporating Meniscus

Clarifying the particle dynamics near an evaporating meniscus in microfluidics makes great sense in many biological and chemical processes such as analyte enrichment, particle detection and cell position control. In the present work, a numerical model is developed to describe the mass transport and particle dynamics near an evaporating meniscus sustained at the outlet of a micro PDMS tube. The micro flow field is simulated in Computational Fluid Dynamics (CFD) approach. Both the evaporation at the liquid-air interface and the vapor diffusion in air are considered. The convection near meniscus caused by the evaporation and Marangoni effect at interface is presented. Discrete Element Method (DEM) is introduced and coupled to CFD to study the particle dynamics in liquid affected by the convection, the gravity and the buoyancy.