Computation of three-dimensional particle trajectories in alternating-current electro-osmotic micropumps
Sprache des Vortragstitels:
COST Action MP0604: Optical Micro-Manipulation by Nonlinear Nanophotonics
Sprache des Tagungstitel:
This work deals with the computation of three dimensional particle trajectories in a microfluidic alternating-current electro-osmotic (aceo) pump channel, including modeling techniques for different length scales to account for nanoscopic effects in a microfluidic device. The pumping channel consists of a periodic electrode array, where in the vicinity of the electrodes electro-osmotic flow arises based on the periodic formation of an electric double layer in the electrolytic fluid. Consequently dielectric particles in the fluid channel are influenced by viscous drag forces due to the resulting electro-osmotic flow and by dielectrophoretic forces due to remaining electric field in the channel. Through modeling the nanoscopic double layer formation with an equivalent circuit model, the two-dimensional electric and flow fields above a pair of electrodes are first solved with finite elements regarding the double layer formation as a boundary. The result of this two-dimensional computation in turn is used as a boundary for the three-dimensional computation of the microfluidic device with the length scale of some millimeters. By means of this computation procedure particle trajectories in complex microfluidic devices can be evaluated regarding nanoscopic physical effects.