To estimate the local Debye length thickness, the coupled set of the Poisson-Boltzmann, momentum, and energy equations are solved numerically in the limit of the lubrication approximation theory (LAT). Also, the ionic distribution and electrical potential based on the non-isothermal Poisson-Boltzmann equation are modified. Consequently, an induced pressure field counterbalances the axial variation of the plug-like electroosmotic velocity to maintain the fluid mass continuity. An imposed electric field be- tween the ends of the microchannel interacts with an ionized viscoelastic fluid causing Joule heating, which induces a temperature gradients along the microchannel, affecting the fluid’s physical properties, and in a notable manner, the ionic distribution into the electric double layer (EDL), resulting in ther- modiffusion. This work theoretically studies the influence of the thermodiffusive effect on the local Debye length thick- ness in a purely electroosmotic flow in a parallel flat plate microchannel. In this paper, recent theoretical, numerical and experimental investigations are covered to provide a better insight both on the operational mechanisms and strategies for lab‐on‐chip applications. Furthermore, electrode configurations and their shapes in different micropumps are explored and categorized to provide conclusive information for the selection of efficient, simple and affordable strategies to transport fluids in microfluidic devices. A detailed description of different mechanisms is presented to provide a comprehensive overview on the key parameters used in electric micropumps. Different electrokinetic mechanisms implemented in electrohydrodynamic‐, electroosmosis‐, electrothermal, and dielectrophoresis‐based micropumps are discussed.
This review attempts to provide a fundamental insight of the various electric‐driven flows in microchannels and their working mechanisms as micropumps for microfluidic devices. Since the emergence of microfluidic technology to transport fluids in microchannels, the electric field has been utilized as an effective dynamic pumping mechanism. Accurate manipulation of fluids in microfluidic devices is an important factor affecting their functions.
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