MSM 2000
MSM 2000
Technical Proceedings of the 2000 International Conference on Modeling and Simulation of Microsystems

Applications: Microfluidics Chapter 13

Modeling of FlowFET Characteristics

Authors: Y.-S. Leung Ki, R.B.M. Schasfoort, S. Sclautmann, Ph. Renaud and A. van den Berg

Affilation: EPFL, Switzerland

Pages: 544 - 547

Keywords: FlowFET, Electrokinetic effects, z-potential, microfluidics, double layer

Classical electrokinetic theory demonstrates that modu-lation of the z-potential at the shear plane can alter both the magnitude and direction of Electroosmotic Flow (EOF) induced in a microchannel at low driving field strengths. In the FlowFET, z-potential is modulated by applying a voltage VG ñ with respect to the driving field cathode ñ through the insulated side walls of the device. An analytical model based on overall charge neutrality is presented which predicts the z-potential as a function of VG. This is compared to values of shear plane z-potential extracted from EOF rate measurement data in a FlowFET. It is found that the model data and experimentally derived values for z-potential are within the same order of magnitude with good agreement between modeled and experimentally observed trends. Discrepancies are due to uncertainties related to experimental observation and lack of Stern layer modeling.

ISBN: 0-9666135-7-0
Pages: 741