A low voltage 3d parallel electroosmotic flow eof pump composed of two electrode layers and a fluid layer is proposed in this work. Microfluidics software from comsol enables study of rarefied. Model single and twophase creeping flow, electrophoretic, electrokinetic. The characteristic analysis of electroosmotic micropump with. Aug 21, 2017 i was wondering how would one go about incorporating an electric field and the requisite chemistry to carry out an electroosmotic simulation in ansys aim or the workbench. Theory, design, and demonstration by shuhuai yao author isbn. Microfluidics software from comsol enables study of. Situated on the banks of river ganges, kanpur city is the commercial capital of the state of uttar pradesh up in india that has a large number of smallscale industries, primarily comprising of textile and leather industries. Oct 15, 2019 microfluidic pump is an essential component in labonchip applications. Comsol multiphysics material models veryst provides the following test programs for comsol multiphysics material models. The simple construction of this type of pumps opens a wide range of applications. World leader in multiphysics simulations hq in stockholm. The flow rates and pumping pressures of eops matches well with micro analysis systems.
During the experiments, applying a multistage nanotube electroosmotic micropump with the same pore size at the two stages yielded a superior performance curve compared to that of the. Electroosmosis and streaming potential are two complementary electrokinetic processes related by the onsager relation. Our model took the advantage of the following predefined templatesphysics interfaces. Development of a high flow rate 3d electroosmotic flow pump. The equations that are solved are the continuity equations for flow velocity and current density together with a mass balance using the electrokinetic flow. Electroosmotic pumping for dewatering sewage sludge. Electroosmotic eo pumps use this effect to generateboth. This method allows applying current densities higher than previously reported. Electroosmotic eo pumpmg is a widely used micro fluidic pumpmg teclmique due to its advantages such as simple design, applicability to wide range of conductive fluids and favorable scaling of electrical forces. Figure 1 shows a single stage with two parts in a cascade.
Electroosmotic pumps possess several outstanding features. Pdf lowvoltage electroosmotic micropump solved with. Theoretical and numerical analysis of lowvoltage cascade. Electroosmotic flow or electroosmotic flow, often abbreviated eof. Aiming at the coupling problems of electrical field and flow field in porous media microchannels, the mathematical model of electroosmotic eo flow is built.
Electroosmotic flow of powerlaw fluids in a slit channel1d is analyzed. Feb 01, 2009 electroosmotic pumps possess several outstanding features. The model uses the predefined electroosmotic flow multiphysics coupling. Comsol multiphysics software provides a powerful modeling platform for modeling of complex fluid dynamic systems, such as rotating. Micropumps, especially those based on electroosmotic flow eof, are essential components. In all cases, working fluid is 1 mm sodium ion concentration borate buffer ph 9. Electroosmotic eo pumps can drive electrolyte liquids with a wide range of conductivities and achieve significant pressures and flow rates in a compact design with no moving parts. Hydrodynamic modeling of a rotating cone pump using comsol.
Using comsol multiphysics, we analyzed a proof of concept of a single zerovoltage electroosmotic flow pump stage using cfd and analytical equivalent. The focus is on the numeric analysis of dceop with comsol multiphysics. 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. Perform multiphysics simulations of microfluidic devices with the microfluidics module. These problems have led to an intense search for more efficient mixers for microfluidic systems. The cell combines pressure and electroosmotic driven flow. Eops are capable of generating constant and pulsefree flows, the flow magnitude and direction of an eop are convenient to control, the pump can be fabricated using standard microfabrication technologies and thus is readily integrateable with labonchip loc devices, and eops have no. On the modeling and simulation of electroosmotic micropump. Description in generating high electroosmotic flows eo for use in microfluidic pumps, a limiting factor is faradaic reactions which are more pronounced at high electric fields. Simulation and experimental study of a porous electroosmotic pump. The characteristics of electroosmotic nanotubes pump constructed using porous alumina membranes with varying pore sizes and at different stages were also analyzed. Therefore, the development of a lowvoltage cascade eof pump is of interest, as they can be powered by batteries and hence be suitable for portable microfluidics devices.
Comsol multiphysics material models veryst engineering. Mathematical modeling of travelingwave electroosmotic. Microfluidic devices require pumps and mixers without moving parts. A lowpower cmos microfluidic pump based on travelling. Particular functionality may be common to several products. Fluorescent latex particles are used to visualize the flow pattern. This is a multidisciplinary software which is widely used by many researchers to model various phenomena 21. Because electroosmotic velocities are independent of conduit size, as long as the. Feb 07, 20 fluid flow generated by a pair of coplanar electrodes energized with ac voltage. Finally, dont forget that comsol is a multiphysics software, allowing you to couple the physics seen in this model to other physics. Nov 24, 2015 pinned ion exchange resin 45m diameter and polystyrene particle7m. Microfluidic pump is an essential component in labonchip applications.
Driving the flow with an electric field allows for the fabrication of pumps and mixers without moving parts. The flow volume and pressure difference of the pump increased rapidly with the input voltage. Electroosmotic flow eof describes the movement of ions through a solute under the control of an applied potential. Because electroosmotic velocities are independent of conduit size, as long. The simulation will be done using comsol multiphysics software.
The electroosmotic pump performance is investigated by experimentally measuring the fluid volume displaced and flow rate. Normalized flow rate and pressure performance of the porous glass eo pump across various parameters pump length, pore size, and applied potential. The equations that are solved are the continuity equations for flow velocity and current density. Users can simulate such applications as compressible gas flows at low pressures, nonnewtonian flows for example, blood flow, and laminar and creeping flows that typically occur in labonachip systems. They use electroosmotic pumping to achieve both significant flow rates and pressures, and a fairly wide range of working electrolytes may be used including deionized water, buffered aqueous electrolytes. The mathematical model involves the microchannel surroundings and several acvoltage driving modes. However, most dc electroosmotic pumps require high voltage, e. The term electroosmotic flow and electroosmosis are generally used interchangeably in the context of micro and nanofluidics. The exposed silanol groups are ionized above ph 3, therefore creating a negatively charged inner capillary surface. Nft has developed micro electroosmotic pumps for micro fluidic systems. A porous membrane for use in an electroosmotic pump for pumping a fluid by electroosmotic transport, the porous membrane comprising. Using optimization module, geometric optimization is carried out to minimize the curveinduced dispersion. The microfluidics module of multiphysics simulation software allows the study of microfluidic devices and rarefied gas flows. The fluid layer contains twenty parallel fluid channels and is set at the middle of the two electrode layers.
This model shows a crosssection of a low voltage cascade micropump. Ravi selvaganapathy, assistant professor mechanical engineering. One application of this is removing liquid flooding water from channels and gas diffusion layers and direct hydration of the proton exchange membrane in the membrane electrode assembly mea of the proton exchange membrane fuel cells. Maximizing fluid delivered by bubble free electroosmotic pump. The characteristic analysis of electroosmotic micropump. Porous glass electroosmotic pumps stanford university. Robust models that allow prediction of pump performance would be useful for guiding new designs for various applications versus using less efficient empirical approaches. Instead of a single electroosmotic pump, the cascade consists of several eof pump stages in series, each with zero net voltage drop. The distance between fluid and electrode channels was controlled to be under 45. Secondly, when i am drawing a channel, how do i indicate the wall material to ensure the correct chemistry for generating the chargeselectric double layer for electroosmosis.
Electroosmotic flow eof pumping has been widely used to manipulate fluids such as liquid sample reagents in microfluidic systems. The system consists of a compartment of sintered porous material and two electrodes that generate an electric field. These devices offer important advantages to more traditional pumping technologies in a. Analysis of electroosmotic flow of powerlaw fluids in a. Fluid flow generated by a pair of coplanar electrodes energized with ac voltage. Electroosmotic micropump for microfluidics from comsol. Electroosmotic flow in porous media comsol multiphysics. In static mixers, also called motionless or inline mixers, a fluid is pumped. In ce, the capillary columns consist of silica with silanol groups exposed on the inner surface. In a previous paper 1, we have described the background and working principle of electroosmotic pumps and presented a detailed pump performance model. Nfts micro electroosmotic pumps generate no pulsations due to the absence of a mechanical driving part, and they achieve high pressure and immediate response time with low operation voltage. I was wondering how would one go about incorporating an electric field and the requisite chemistry to carry out an electroosmotic simulation in ansys aim or the workbench.
Electric currents, creeping flow, and transport of diluted species. This model takes advantage of electroosmosis to mix fluids. 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. It models the applied electric field in the fluid and the resulting electroosmotic flow through the pump. During the experiments, applying a multistage nanotube electroosmotic micropump with the same pore size at the two stages yielded a superior performance curve compared to that of the singlestage nanotube electroosmotic micropump. With the effect of electro osmosis, it is possible to generate a continuous, bidirectional, impulsefree stream of electrolyte fluid. Comsol includes an electroosmotic velocity boundary condition that ignores the flow field between the wall and the slipping plane, and analytically computes the velocity at the wall based on the zeta potential using the helmholtzsmoluchowski relation. This comsol multiphysics model of a peristaltic pump is a combination of structural mechanics to model the squeezing of the tube and fluid dynamics to compute the fluids motion. Electroosmotic pumping is receiving increasing attention in recent years owing to the rapid development in micro total analytical systems. Simulation of highly nonlinear electrokinetics using a. Oct 28, 20 comsol includes an electroosmotic velocity boundary condition that ignores the flow field between the wall and the slipping plane, and analytically computes the velocity at the wall based on the zeta potential using the helmholtzsmoluchowski relation. This model studies the dispersion of neutral species band through curved microchannel in an electroosmotic flow eof. Optimizing band dispersion in an electroosmotic flow.
Pdf numerical analysis of non newtonian fluid flow in a low. More importantly, the formation of an electroosmotic pump is dependent on the nature of the soil. Modeling electroosmotic flow and the electrical double layer. The time taken for gas bubbles to start forming on an electrode operates in a stagnant aqueous solution is driven by. These reactions lead to bubble generation at the electrodes and pump efficiency reduction. For a single microchannel, the influence of voltage on velocity and joule heat is analyzed by using coventorware. Compared with other micropumps, electroosmotic pumps eops offer a number of advantages such as creation of constant pulsefree flows and elimination of moving parts. Comsol is the developer of comsol multiphysics software, an interactive environment for modeling and simulating scientific and engineering problems. The governing equations are the poissonboltzmann equation, the cauchy momentum equation, generalized smoluchowski equation and the continuity equation are used to get shear stress, dynamic viscosity, and velocity distribution. Modeling electroosmotic flow and the electrical double. Electroosmotic pumps and their applications in microfluidic. Aiming at the coupling problems of electrical field and flow field in porous media microchannels, the mathematical model of electroosmoticeo flow is built. This example treats the modeling of electroosmotic flow in porous media.
It is of importance to develop an active microfluidic pump with lowpower and lowcost characteristics for portable and. This effect leads to a high pressure inside of the capillaries of the electroosmotic pump. Numerical model in a singlechannel eof pump, the electroosmotic flow velocity at the solidliquid interface of the pumping channel can be written as. Numerical analysis shows that the velocity is proportional to the voltage and the joule heat is small and. A lowpower cmos microfluidic pump based on travellingwave. In this paper, modeling and simulation of electroosmotic micropump using nonnewtonian fluid like blood will be conducted to investigate its performance. Dean advanced waste treatment research laboratory cincinnati, ohio july, 1970. An electroosmotic pump eop, or eo pump, is used for generating flow or pressure by use of an electric field. Pdf numerical analysis of non newtonian fluid flow in a. In his keynote talk at the comsol conference 2018 lausanne, andri bezzola of samsung presents case studies for how he uses the comsol multiphysics software and simulation applications to design high.
In this chapter, we will introduce the research progress on eof pumps in the fields of microfluidic science and technology and briefly present their microfluidic applications in recent years. Electric properties of the cytoplasm and nucleus were taken from the experimental study as. Chemical reaction engineering module examples comsol. The chapter focuses on pump channel materials, electrodes, and their. Our model yields analytical expressions for the electroosmotic. This investigation is based on numerical simulation using comsol multiphysics software. In addition, we discuss topics such as how to treat the electrical double layer and turning a model into a userfriendly simulation app. Warning your internet explorer is in compatibility mode and may not be displaying the website correctly. 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.
Veryst can use its extensive expertise to recommend an appropriate combination of test program and material model if you are unsure of what test program is required for your application. The weak form has been used for handling singularities and other problems. The application gallery features comsol multiphysics tutorial and demo app files. The electric charge relaxation time is determined by s, where dielectric permittivity of vacuum. This contribution is devoted to the mathematical modeling of the ac electroosmotic micropumps in comsol multiphysics and matlab. Bubble free electrodes for electroosmotic pumping balasubramanian ganapathy subramani, b. Indiscriminate disposal of wastes is a serious concern, especially in kanpur, a major industrial town in central india. In addition to the core comsol, the software package included mems module and microfluidics module.
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