Electrokinetic pumping using packed microcapillary

Electrokinetic micropumps are fabricated using 6-8 mu m ODS beads into 320-700 mu m fused-silica capillaries. The fabricated bead column is characterized by measuring the porosity and tortuosity. Experiments are carried out to study the flow characteristics under the effects of the packing conditions, solution properties and applied electric field strength. Specifically, the EO flow rates are measured using two independent methods: the test column method and the electric current monitoring method. Thus, the zeta potential of the packing beads can be obtained. In addition, a theoretical model is presented, and the theoretical predictions are found in reasonable agreement with the experimental data. (c) 2006 Elsevier B.V. All rights reserved.