Introductory electrostatics concepts required for an integral boundary layer analysis of the electrical double layer to predict electroosmotic flow. The book in your hands, the acdc module model library, provides details. Dalton1 1university of calgary, calgary, ab, canada abstract electrokinetics has many applications in a wide range of areas, such as labonachip and. I checked everything with the old comsol library model electrokinetic flow in biochip3. The ac electroosmosis is mostly based on the coulombic interaction between an. The comsol multiphysics software requires discretization of spatial. How do i make a nonlinear solver converge in comsol multiphysics. By definition, electroosmosis refers to the motion of a liquid induced by an applied potential across a microchannel. This model takes advantage of electroosmosis to mix fluids. These problems have led to an intense search for more efficient mixers for microfluidic systems. Because electroosmotic velocities are independent of conduit size, as long as the electrical double layer is much smaller. The equations that are solved are the continuity equations for flow velocity and current density together with a mass balance using the electrokinetic flow. Electroosmosis also electroendosmosis, the movement of a liquid through capillaries or porous diaphragms upon application of an external.
The microfluidics module provides a specialized electroosmotic velocity boundary condition as one of several fluid wall boundary conditions. Electroosmotic flow in porous media comsol multiphysics. Multiphysical modeling of dc and ac electroosmosis in. Ac electroosmosis, ac electrothermal, induced charge electroosmosis, traveling wave dielectrophoresis, and liquid dielectrophoresis. Mathematical modeling of ac electroosmosis in microfluidic and. The numerical simulations are performed using the finite analysis software comsol multiphysics version 3. The term electroosmotic flow and electroosmosis are generally used interchangeably in the context of micro and nanofluidics. In this article, enhancement of heterogeneous immunoassays using ac electroosmosis was studied through the use of finite element modeling and fluorescent immunoassays.
Ac electroosmosis and dielectrophoresis for trapping. Simulations of interdigitated planar electrodes indicate that optimum electrode geometry electrode width and spacing scales with the chamber height and that binding times can. Find out all of the information about the comsol product. Learn how to model microfluidic devices in comsol, such as. Geometry and dimensions of the microchannel l1 l5 h 10. Can anyone help with the following error in comsol. Did you know that designing electrical systems and devices is faster and cheaper with simulation. We report the presence of trapping points near the vertex of the triangular electrode in our simulation. You can try fluent software which uses the finite volume that is so. In smallscale microfluidics processes, electroosmosis, electrothermal effects, and electrokinetic instabilities are responsible for fluid motion and electrophoresis and dielectrophoresis dep cause particle movement, such as in cells.
Numerical study on ac electroosmosis in microfluidic channels. Comsol webinar modeling coils and electric devices youtube. This stepbystep instructional video shows you how the electromechanics interface in comsol multiphysics couples and solves mechanical and electrical problems. Author links open overlay panel kuanrong huang a zhou. Driving the flow with an electric field allows for the fabrication of. Ac electrothermal flow pumping acet body force posted 16. The products, devices, and components you design for the static or lowfrequency range need to operate safely in the real world. Electroosmotic flow or electroosmotic flow, often abbreviated eof. This study mainly focuses on ac electroosmosis aceo, which originates from the electric double layer. Poisson equation based modeling of dc and ac electroosmosis.
The analytes in the system are positively charged sodium and a negative ion with the same. This example treats the modeling of electroosmotic flow in porous media. The system consists of a compartment of sintered porous material and two electrodes that generate an electric field. By definition, electroosmosis refers to the motion of a liquid induced by. Driving the flow with an electric field allows for the fabrication of pumps and mixers without moving parts. Pdf numerical simulation of the electrical double layer based on. The numerical analysis was carried out in comsol multiphysics software. In order to solve governing equations of ac electroosmosis, a commercial software comsol multiphysics is implemented. Extensive information about command line modeling using comsol script is available in yet another book, the comsol multiphysics scripting guide. It is a common practice to optimize the design of inkjet printers, labonachip devices, and cell sorters with microfluidics simulation software. Nonplanar asymmetric electrodes, on which an ac electric field is imposed, are deposited on one channel wall. Microfluidic mixing on application of traveling wave. Does anyone know why the ellectroosmotic flow is not a flat profile in comsol or i messed it up. Acdc module modeling software electromagnetic field.
Comsol uses finite element in order to solving problems. In addition to using multiphysics modeling for your own projects, you can also turn your models into simulation applications and digital twins for use by other design teams. Its spatial characteristics are 100 microns wide by fifty microns long. In electroosmosis, the uncompensated ions in the charged electric double layer edl present on the fluid surfaces are moved by an electric field, causing a net fluid flow. Computer simulations were performed within the comsol 4. Currently available theoretical models for eo flows were embedded in the software and solved numerically to evaluate the effects of channel geometry, frequency of. The analytes in the system are positively charged sodium and a.
The ac electroosmosis is mostly based on the coulombic interaction between an imposed ac electric field and a mobile electric charge temporally arising at electrolyte metal electrode interfaces. Electroosmotic flow eof describes the movement of ions through a solute under the control of an applied potential. Poissonboltzmann models for ac electroosmosis flows. In the field of microfluidics, the flow is often driven by an electric field. Particular functionality may be common to several products. After watching this video, you will have a solid foundation for creating models of. Therefore, the development of a lowvoltage cascade eof pump is. The first model demonstrated that the presence of electroosmosis might intensify the flux of messenger proteins to the nucleus and allow the efficient transport of the negatively charged phosphorylated messenger proteins against the electrostatic repulsion of the.
Murdoch for teaching me cfd simulation with comsol multiphysics, mr. Timothy pruett for helping me making sinusoidal spacers with 3d printing, the students in the creative inquiry program for setting up the bench scale ro system. Fast biofluid transport of high conductive liquids using ac electrothermal phenomenon, a study on substrate characteristics a. Overview classical electrokinetic phenomena, such as electroosmotic flow and electrophoresis, are linear in the applied voltage and thus cannot produce any net flow under alternating current. The model equations are solved using the finite element software comsol. Ac electro osmosis aceo is a nonlinear electrokinetic phenomenon of inducedcharge electroosmotic flow around electrodes applying an alternating voltage. Numerical modeling and analysis of electro osmotic. In addition, we discuss topics such as how to treat the electrical double layer and turning a model into a userfriendly simulation app. Lowvoltage electroosmotic micropump solved with comsol. Mathematical modeling of ac electroosmosis in microfluidic and nanofluidic chips using equilibrium and nonequilibrium approaches article in journal of applied electrochemistry 405. A set of auxiliary variables to characterize the ac micropump was defined, see the supplementary material. Model of electrokineticflow driven by an ac electric field in a microchannel. The implementation procedure of this multiphysical problem in a cfd software and.
Electroosmotic flow is the bulk liquid motion that results when an externally applied electric field interacts with the net surplus of charged ions in the diffuse part of an electrical double layer. Strongly nonequidistant and anisotropic meshes of finite elements had to be used due to formation of thin edls. It allows conventional physicsbased user interfaces and coupled systems of partial differential equations pdes. Comsol multiphysics is a crossplatform finite element analysis, solver and multiphysics simulation software.
Bidirectional flow induced by an ac electroosmotic micropump with dc voltage bias. In ce, the capillary columns consist of silica with silanol groups exposed on the inner surface. Customize comsol multiphysics to meet your simulation needs with applicationspecific modules. Simulation of reverse osmosis and osmotically driven. Everything in my simulation looks ok but the flow profile looks weird. Modeling electroosmotic flow and the electrical double. In our research group, we usually employ comsol multiphysics software for both the stationary and the nonstationary simulations. Simulating electrokinetic phenomena in microfluidics. Simply log in and follow the onscreen product download directions.
Electroosmosis article about electroosmosis by the free. To account for the steric comsol multiphysics software application effects of the. Numerical simulation of the electrical double layer based on the. An experimental study of 3d electrodefacilitated particle traffic. Contact a supplier or the parent company directly to get a quote or to find out a price or your closest point of sale.
To generate acffet, a gate electrode ge is placed inside an. View the specification chart to find your ideal combination. Numerical simulation of the electrical double layer based. Comsol provides an ide and unified workflow for electrical, mechanical, fluid, acoustics and chemical applications. Microfluidics electrostatics fundamentals related to. Keywords tas, biomems, electroosmosis, comsol multiphysics. The purpose of this study is presenting an active micromixer, which is based on ac electroosmotic flow driven on 3d micro wires. Introduction 5 introduction the ac dc module is used by engineers and scientists to understand, predict, and design electric and magnetic fields in statics and lowfrequency applications. Modeling electroosmotic flow and the electrical double layer. The combination of comsol products required to model your application depends on several factors and may include boundary conditions, material properties, physics interfaces, and part libraries.
How to model electromechanics in comsol multiphysics. Comsol multiphysics electric currents physics and laminar flow physics are used to simulate dielectrophoresis and ac electroosmosis. Microfluidic mixing on application of traveling wave electroosmosis. Watch this archived webinar to learn how to model electroosmotic flow, a useful skill for optimizing devices like micropumps and micromixers, with the comsol multiphysics software and addon microfluidics module. In order to carry out the numerical simulations, a strongly anisotropic mesh of finite elements is developed. Fieldeffect control on nonlinear electroosmosis in the transverse direction greatly. Bidirectional flow induced by an ac electroosmotic. Simulating electroosmotic flow with the microfluidics module. The cell combines pressure and electroosmotic driven flow. Mathematical modeling of ac electroosmosis in microfluidic. The numerical results were generated through simulations performed using comsol 3. Multiphysical modeling of dc and ac electroosmosis. Modeling of an acelectroosmosis based microfluidic mixer. Enhancement of heterogeneous immunoassays using ac.