Numerical Simulation of Microfluidic Flow Using a Combination of Micro and Macro Computational Techniques: Scaling Issues

T. Mautner
SPAWAR Systems Center San Diego, US

Keywords: Microfluidics, Lattice Boltzmann, Convection-Diffusion, Scaling, Simulations

Abstract:
Recent literature has demonstrated the possibilities of using configurable surfaces to enhance the flow of fluids in MEMS devices. Not only are surface properties important in fluid delivery, the inherent problems of mixing by diffusion in microfluidic laminar flow needs to be over come to provide more efficient fluidics for bio-sensors. While investigating the use of synthetic jets for fluid mixing in MEMS devices, it was necessary to compute both the fluid flow and concentration fields. The Lattice Boltzmann Method (LBM) has been used to compute the flow field data. The micro formulation of LBM was supplemented with a macro-scale, finite difference formulation of the convection-diffusion equation. While this seems easy enough, it became apparent that the main issue with this hybrid approach is proper scaling of the grid spacing and time increment. This work presents the results of the hybrid method as applied to Re<150 flows concentrating on the microfluidic regime of Re<10. The computation method uses algorithms which have been compared to results found in the literature, and provides simulations showing the effects of grid size and time increment scaling.

NSTI Nanotech 2003 Conference Technical Program Abstract