1 / 14

ELECTRO-OSMOTIC FLOW

ELECTRO-OSMOTIC FLOW. Shahrood University Of Technology. Presenter : Ahmad Hadadan 9124494 Adviser : Dr.Nazari. 1 /14. Pressure Driven Flows. This flow is caused by the pressure gradient at up & down stream of channel.

semah
Télécharger la présentation

ELECTRO-OSMOTIC FLOW

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. ELECTRO-OSMOTIC FLOW ShahroodUniversity Of Technology Presenter : Ahmad Hadadan 9124494 Adviser : Dr.Nazari 1/14

  2. Pressure Driven Flows This flow is caused by the pressure gradient at up & down stream of channel. One of the basic laws of fluid mechanics for pressure driven laminar flow : no-slip boundary condition = velocity at the walls must be zero. This produces a parabolic velocity profile within the channel . Pressure Driven -Electrokinetic EDL Electrophoresis -Electroosmotic Pumping 2/14

  3. Electrokinetically Driven Flows Electrokinetic phenomena are based on : - the interaction of the applied electric field + with a layer of electrical charges on a solid surface + in contact with an aqueous electrolyte solution + in microchannels . Pressure Driven -Electrokinetic EDL Electrophoresis -Electroosmotic Pumping 3/14

  4. fundamental assumption is : the linear response of the electrokinetic motion with respect to the applied electric field and the fixed static surface chargeson non-conducting solid surface . 1 - Electrophoresis 2 - Electroosmosis Pressure Driven -Electrokinetic EDL Electrophoresis -Electroosmotic Pumping 4/14

  5. EDL (Electrical Double Layer) A layer of mobile ions, known as an electrical double layer, forms in the region near the interface When an electric field is applied to the fluid (usually via electrodes placed at inlets and outlets), the net charge in the electrical double layer is induced to move by the resulting force. Pressure Driven -Electrokinetic EDL Electrophoresis -Electroosmotic Pumping 5/14

  6. Electrophoresis Flow • Electrophoresis is the motion of dispersed particlesrelative to a fluid under the influence of a uniform electric field Pressure Driven -Electrokinetic EDL Electrophoresis -Electroosmotic Pumping 6/14

  7. ElectroosmoticFlow (EOF) Electroosmotic flowis : - the motion of liquid that includes ions - induced by an applied potential - across a porous material, capillary tube, membrane, microchannel, or any other fluid conduit Example ) Na Cl Pressure Driven -Electrokinetic EDL Electrophoresis -Electroosmotic Pumping 7/14

  8. Generally, electrokinetically-driven flows in microchannelsare laminar because of the slow velocity and small characteristiclength scale and thus small Reynolds number . Pressure Driven -Electrokinetic EDL Electrophoresis -Electroosmotic Pumping No slip condition 8/14

  9. The resulting flow from applying a voltage ,Unlike a parabolic profile flow generated from a pressure differential, this flow’s velocity profile is approximately planar, with slight variation near the electric double layer . Pressure Driven -Electrokinetic EDL Electrophoresis -Electroosmotic Pumping Velocity Profile of ElectroosmoticFlow 9/14

  10. Comparison Between : Pressure Driven Flow & Electroosmotic Flow Pressure Driven -Electrokinetic EDL Electrophoresis -Electroosmotic Pumping 10/14

  11. Development Of EOF non-conducting hurdles Pressure Driven -Electrokinetic EDL Electrophoresis -Electroosmotic conducting hurdles Pumping 11/14

  12. Electroosmotic Pumps (EOPs) • An electrokineticeffect known as electroosmosiscan be used to pump liquids at the microscale Pressure Driven -Electrokinetic EDL Electrophoresis -Electroosmotic Pumping 12/14

  13. References • [1] YasamanDaghighia, Yandong Gao, Dongqing Li .umerical study of induced-charge electrokinetic motion of heterogeneous particle in a microchannel . ElectrochimicaActa56 (2011) 4254–4262 • [2] Zhemin Wu ,Dongqing Li . Micromixing using induced –charge electrokinetic flow .ElectrochimicaActa 53(2008) 5827-5835 13/14

  14. Thanks For Your Attention 14/14

More Related