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. Microfluidics software from comsol enables study of. This investigation is based on numerical simulation using comsol multiphysics software. 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. A porous membrane for use in an electroosmotic pump for pumping a fluid by electroosmotic transport, the porous membrane comprising. 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. The distance between fluid and electrode channels was controlled to be under 45. Electroosmotic pumping for dewatering sewage sludge. The small size is very attractive for labonachip loc experiments.
Electroosmotic eo pumps use this effect to generateboth. These reactions lead to bubble generation at the electrodes and pump efficiency reduction. The time taken for gas bubbles to start forming on an electrode operates in a stagnant aqueous solution is driven by. 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. Optimizing band dispersion in an electroosmotic flow. Aiming at the coupling problems of electrical field and flow field in porous media microchannels, the mathematical model of electroosmotic eo flow is built. The chapter focuses on pump channel materials, electrodes, and their. Comsol multiphysics material models veryst provides the following test programs for comsol multiphysics material models.
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. The characteristic analysis of electroosmotic micropump. Oct 15, 2019 microfluidic pump is an essential component in labonchip applications. Comsol is the developer of comsol multiphysics software, an interactive environment for modeling and simulating scientific and engineering problems. 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. These problems have led to an intense search for more efficient mixers for microfluidic systems. Electroosmotic pumping is receiving increasing attention in recent years owing to the rapid development in micro total analytical systems.
Electroosmotic flow in porous media comsol multiphysics. This is a multidisciplinary software which is widely used by many researchers to model various phenomena 21. It models the applied electric field in the fluid and the resulting electroosmotic flow through the pump. Theory, design, and demonstration by shuhuai yao author isbn. 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.
However, most dc electroosmotic pumps require high voltage, e. The simulation will be done using comsol multiphysics software. Bubble free electrodes for electroosmotic pumping balasubramanian ganapathy subramani, b. In all cases, working fluid is 1 mm sodium ion concentration borate buffer ph 9. Electroosmotic pumps and their applications in microfluidic.
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. Robust models that allow prediction of pump performance would be useful for guiding new designs for various applications versus using less efficient empirical approaches. Numerical analysis shows that the velocity is proportional to the voltage and the joule heat is small and. An electroosmotic pump eop, or eo pump, is used for generating flow or pressure by use of an electric field. 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. 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. Numerical analysis of electroosmotic flow through capillaries. Simulation and experimental study of a porous electroosmotic pump. Fluorescent latex particles are used to visualize the flow pattern.
A lowpower cmos microfluidic pump based on travellingwave. The equations that are solved are the continuity equations for flow velocity and current density together with a mass balance using the electrokinetic flow. 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. Figure 1 shows a single stage with two parts in a cascade. Using optimization module, geometric optimization is carried out to minimize the curveinduced dispersion. The simple construction of this type of pumps opens a wide range of applications. Pdf numerical analysis of non newtonian fluid flow in a. Finally, dont forget that comsol is a multiphysics software, allowing you to couple the physics seen in this model to other physics. The mathematical model involves the microchannel surroundings and several acvoltage driving modes. The system consists of a compartment of sintered porous material and two electrodes that generate an electric field. A 2d model is used for one pumping stage to examine the pumping pressure and flow rate of blood using electroosmotic micropump.
Micropumps, especially those based on electroosmotic flow eof, are essential components. Particular functionality may be common to several products. 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 static mixers, also called motionless or inline mixers, a fluid is pumped. 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. Our model yields analytical expressions for the electroosmotic. 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. Electroosmotic micropump for microfluidics from comsol. The cell combines pressure and electroosmotic driven flow. The flow volume and pressure difference of the pump increased rapidly with the input voltage. Electric properties of the cytoplasm and nucleus were taken from the experimental study as. 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. The characteristic analysis of electroosmotic micropump with.
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. Fluid flow generated by a pair of coplanar electrodes energized with ac voltage. Analysis of electroosmotic flow of powerlaw fluids in a. 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. Model single and twophase creeping flow, electrophoretic, electrokinetic. Nov 24, 2015 pinned ion exchange resin 45m diameter and polystyrene particle7m. In addition to maintaining a high electroosmotic flow rate, the electroosmotic pump also increases the degree of saturation of the soil in the initial period itself, thereby increasing the effective crosssectional area for the removal of crvi. It is of importance to develop an active microfluidic pump with lowpower and lowcost characteristics for portable and.
A low voltage 3d parallel electroosmotic flow eof pump composed of two electrode layers and a fluid layer is proposed in this work. Compared with other micropumps, electroosmotic pumps eops offer a number of advantages such as creation of constant pulsefree flows and elimination of moving parts. 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. Pdf numerical analysis of non newtonian fluid flow in a low. Our model took the advantage of the following predefined templatesphysics interfaces. This example treats the modeling of electroosmotic flow in porous media. 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. Porous glass electroosmotic pumps stanford university. Instead of a single electroosmotic pump, the cascade consists of several eof pump stages in series, each with zero net voltage drop.
Electroosmotic pumps possess several outstanding features. The flow rates and pumping pressures of eops matches well with micro analysis systems. Feb 07, 20 fluid flow generated by a pair of coplanar electrodes energized with ac voltage. The term electroosmotic flow and electroosmosis are generally used interchangeably in the context of micro and nanofluidics. The model uses the predefined electroosmotic flow multiphysics coupling. The microfluidics module of multiphysics simulation software allows the study of microfluidic devices and rarefied gas flows. The weak form has been used for handling singularities and other problems. Warning your internet explorer is in compatibility mode and may not be displaying the website correctly. Nft has developed micro electroosmotic pumps for micro fluidic 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. The characteristics of electroosmotic nanotubes pump constructed using porous alumina membranes with varying pore sizes and at different stages were also analyzed. The fluid layer contains twenty parallel fluid channels and is set at the middle of the two electrode layers. Because electroosmotic velocities are independent of conduit size, as long as the. Microfluidic devices require pumps and mixers without moving parts. Microfluidic pump is an essential component in labonchip applications. Normalized flow rate and pressure performance of the porous glass eo pump across various parameters pump length, pore size, and applied potential. With the effect of electro osmosis, it is possible to generate a continuous, bidirectional, impulsefree stream of electrolyte fluid. In a previous paper 1, we have described the background and working principle of electroosmotic pumps and presented a detailed pump performance model. Ravi selvaganapathy, assistant professor mechanical engineering. This effect leads to a high pressure inside of the capillaries of the electroosmotic pump. In addition to the core comsol, the software package included mems module and microfluidics module.
World leader in multiphysics simulations hq in stockholm. Indiscriminate disposal of wastes is a serious concern, especially in kanpur, a major industrial town in central india. Maximizing fluid delivered by bubble free electroosmotic pump. Hydrodynamic modeling of a rotating cone pump using comsol. Electroosmotic flow eof describes the movement of ions through a solute under the control of an applied potential. This model studies the dispersion of neutral species band through curved microchannel in an electroosmotic flow eof.
Using comsol multiphysics, we analyzed a proof of concept of a single zerovoltage electroosmotic flow pump stage using cfd and analytical equivalent. Electroosmotic flow of powerlaw fluids in a slit channel1d is analyzed. The exposed silanol groups are ionized above ph 3, therefore creating a negatively charged inner capillary surface. On the modeling and simulation of electroosmotic micropump. 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. This contribution is devoted to the mathematical modeling of the ac electroosmotic micropumps in comsol multiphysics and matlab. The focus is on the numeric analysis of dceop with comsol multiphysics. For a single microchannel, the influence of voltage on velocity and joule heat is analyzed by using coventorware. Simulation of highly nonlinear electrokinetics using a. Mathematical modeling of travelingwave electroosmotic. More importantly, the formation of an electroosmotic pump is dependent on the nature of the soil. Electroosmotic flow or electroosmotic flow, often abbreviated eof.
Theoretical and numerical analysis of lowvoltage cascade. Comsol multiphysics material models veryst engineering. 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. This method allows applying current densities higher than previously reported. The timescale of the intracellular biological processes is. The equations that are solved are the continuity equations for flow velocity and current density.
Electroosmotic flow eof pumping has been widely used to manipulate fluids such as liquid sample reagents in microfluidic systems. Driving the flow with an electric field allows for the fabrication of pumps and mixers without moving parts. The electric charge relaxation time is determined by s, where dielectric permittivity of vacuum. Development of a high flow rate 3d electroosmotic flow pump. 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.
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. The electroosmotic pump performance is investigated by experimentally measuring the fluid volume displaced and flow rate. Optimal pulse voltage waveform opw are calculated based on the previous theories for different current densities and electrolyte molarity. Comsol multiphysics software provides a powerful modeling platform for modeling of complex fluid dynamic systems, such as rotating. Simulating electroosmotic flow with the microfluidics module. Aiming at the coupling problems of electrical field and flow field in porous media microchannels, the mathematical model of electroosmoticeo flow is built. Microfluidics software from comsol enables study of rarefied. Perform multiphysics simulations of microfluidic devices with the microfluidics module.
This model shows a crosssection of a low voltage cascade micropump. In addition, we discuss topics such as how to treat the electrical double layer and turning a model into a userfriendly simulation app. In ce, the capillary columns consist of silica with silanol groups exposed on the inner surface. Modeling electroosmotic flow and the electrical double. Numerical model in a singlechannel eof pump, the electroosmotic flow velocity at the solidliquid interface of the pumping channel can be written as. These devices offer important advantages to more traditional pumping technologies in a. Electroosmosis and streaming potential are two complementary electrokinetic processes related by the onsager relation. A lowpower cmos microfluidic pump based on travelling. Dean advanced waste treatment research laboratory cincinnati, ohio july, 1970. This model takes advantage of electroosmosis to mix fluids. Feb 01, 2009 electroosmotic pumps possess several outstanding features. Electric currents, creeping flow, and transport of diluted species. In this paper, modeling and simulation of electroosmotic micropump using nonnewtonian fluid like blood will be conducted to investigate its performance. 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.
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