Computational Studies of Interfacial Dynamics in Microfluidics via a 3D Spectral Boundary Integral Algorithm

Abstract

Interfacial dynamics in micron-sized geometries is getting more attention as technologies evolve towards small scales. In pharmaceutical and biochemical applications, fluid droplets moving in microfluidic channels are utilized as “micro-reactors” to precisely control the reaction rate and enhance the mixing efficiency of the reagents. In emulsion generations, low polydispersity of droplets is achieved by the “passive” fission, fusion and sorting of droplets in microfluidic channels. In nanolithography, a micron/nano sized fluid bridge forms between the substrate and the depositing tip. The ability to numerically simulate in a fast and accurate manner the behavior of a small volume of fluid in microfluidic systems is thus demanded. We utilize a 3D Spectral Boundary Element algorithm for interfacial dynamics in microfluidics that exploits all the benefits of the spectral methods (i.e. exponential convergence and numerical stability) but it is not affected by the disadvantage of the spectral methods used in volume discretization to create denser systems. We consider the deformation and migration of droplets in a square microfluidic channel. We investigate the behavior for a single droplet. The effects of droplet size, flow rate and viscosity ratio will be presented.