The effects of the electrical double layer near the solid-liquid nels, where the theory is well developed and documented (1), interface and the induced electrokinetic field on the pressureno widely accepted theories have been established for the interdriven liquid flow through a rectangular microchannel are ananal flow through microchannels, of which the hydraulic diamelyzed in this work. A nonlinear, two-dimensional Poisson -Boltzter usually is about micrometers in the order of magnitude.
mann equation governing the electrical double layer field in the
The fluid flow behavior in these microchannels may be strongly cross section of rectangular channels is numerically solved with influenced by the channel wall effect and hence deviates from the use of a finite-difference scheme. A body force caused by the that described by the traditional form of the Navier-Stokes electrical double field and the flow-induced electrokinetic field is (N-S) equation.
considered in the equation of motion. An exact solution to this equation of motion in rectangular microchannels is obtained by
Tuckerman and Pease (2) appear to have been the first to employing the Green function formulation. The effects of the employ rectangular microchannels as high-performance heat ionic concentration of the liquid, the zeta potential of the solid sinks for cooling electronic components. They found the experisurface, and the size and the shape of microchannels on the fluid mental results of flow friction were slightly higher than those velocity distribution, streaming potential, volumetric flow rate, predicted by classical theories. Several other investigators confriction coefficient, and apparent viscosity are discussed. The firmed this similar, anomalous behavior for microchannel flow results clearly show that for a liquid solution of low ionic concenin their studies. Muhammad and Gui (3) measured water flow tration and a solid surface of high zeta potential the liquid flow in silicon wafer microchannels with different ratios of height in rectangular microchannels is significantly influenced by the to width. Their results showed that the friction coefficient has presence of the electrical double layer field and hence deviates the same pattern as Tuckerman's. Urbanek et al. (4) investifrom the flow characteristics described by classical fluid mechangated liquid flow through 5, 12, and 25 mm hydraulic diameter ics.