Dynamics and Manipulation of Microbeads in ACEO Micropumps
Sprache des Vortragstitels:
22nd international Symposium on Microscale Bioseparations and Methods for System Biology
Sprache des Tagungstitel:
We present a novel approach for particle manipulation in alternating current electro-osmotic (ACEO) micropumps, which is based on the development of electro-osmotic flow of a symmetric electrolyte over a harmonically driven electrode array on the channel bottom. Thereby the particle dynamics is influenced by viscous, gravitational and buoyancy, as well as dielectrophoretic forces due to the incomplete screening of the driving electrodes. Flow, electric field and particle dynamics in the channel are investigated by means of a finite element analysis, where the finite double layer approach and the Gouy-Chapman-Stern theory for the accumulation of ions in the EDL are applied. The numerical analysis is focused on the evaluation of the mean particle propagation velocity regarding the above mentioned forces, where the obtained values are compared to measurements of the particle velocity in an ACEO micropump realized in SU8/glass technology. The dependency of the mean particle velocity on driving voltage, frequency and parti-cle properties gives rise to a novel type of particle manipulation and separation.