Web Release Date: March 3,
Induced Pressure Pumping in Polymer Microchannels via Field-Effect Flow Control
and
Department of Mechanical Engineering, and Bioengineering Program, and Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, and Calibrant Biosystems, Rockville, Maryland 20855
Received for review July 11, 2003. Accepted January 28, 2004.
Abstract:
Microfluidic field-effect flow control (FEFC) modifies the
potential of electroosmotic flow using a transverse
electric field applied through the microchannel wall.
Previously demonstrated in silicon-based and glass microsystems, FEFC is presented here as an elegant method
for flow control in polymer-based microfluidics with a
simple and low-cost fabrication process. In addition to
direct FEFC flow modulation, independent transverse
electric fields in connected microchannels are demonstrated to produce a differential pumping rate between the
microchannels. The different electroosmotic pumping
rates formed by local potential control induce an internal
pressure at the microchannel intersection, resulting in
hydrodynamic pumping through an interconnecting field-free microchannel. Modulation of the voltages applied to
the gate electrodes adjusts the magnitude and direction
of the bidirectional pressure pumping, with fine resolution
volume flow rates from -2 to 2 nL/min in the field-free
microchannel demonstrated.
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