Electroosmosis Flow Research Articles

Effect of induced charge forming active vortex structures in serpentine microchannels on fluid mixing driven by pressure flow

The incorporation of induced charge into the serpentine curved micromixers driven by negative pressure (Np) can serve as an efficacious way for improving micromixing quality. To comprehensively investigate the hydraulic characteristics and mixing capacity of this model, an investigation is conducted using finite element method. The results indicate that when |−30| Pa ≤ Np ≤ |−50| Pa, active vortex pairs formed by electroosmosis flow on the conductive plate surface are fully developed, which strengthens the chaotic convection and leads to a uniform mixing. For |−50| Pa < Np ≤ |−200| Pa conditions, the compression of pressure flow causes the separation and degradation of active vortex pairs. However, increasing the electric field intensity around the conductive plate, such as forming a shrinking microchannel, or increasing the induction area of the plate, such as rotating the conductive plate, can make the active vortex play a beneficial role again, as both the Zeta potential and slip velocity on the plate surface are enhanced. For |−200| Pa < Np ≤ |−500| Pa conditions, the pressure flow gradually dominates the mixing process. But the conductive plate with combined optimal parameters can increase the mixing quality to above 0.8 when Np varies in border range.

Thermal radiation effect in electroosmosis regulated peristalsis transport of Williamson hybrid nanofluid via an asymmetric tapered channel

AbstractElectroosmosis effects in a peristaltic transport of nanofluids are significant for developing the biomimetic pumping structure at a microscopic extent in physiological medications, for instance, ocular drug delivery systems. The present article addresses the numerical assessment of a peristaltically driven electro‐osmotic flow of a Williamson hybrid nanofluid. The flow is intended to be two‐dimensional, incompressible, unsteady, and subjected to an asymmetric tapered micro‐channel. The characteristics of hybrid nanofluid, which consists of silver (Ag) and copper (Cu) as nanoparticles with base fluid‐blood, are explored in a relative manner with regular nanofluid Ag‐blood. Further, the study includes the impact of linear thermal radiation, energy dissipation through viscosity and resistance phenomena with an externally applied consistent magnetic field. The mathematical model is simplified using dimensionless similarity transformations and numerically solved via MATLAB software. Variations in momentum, thermal energy, and entropy generation against various emerging physical parameters are deliberated through graphical results. Longitudinal velocity towards the center line and heat transfer rate is also analyzed through numerical data illustrated in table form. This study introduces a novel mathematical model for the peristaltically driven electroosmosis flow of Ag‐Cu/blood hybrid nanofluid in a tapered asymmetric microchannel, incorporating external electric and magnetic field effects.

Flexible and simultaneous multi-scale bioparticle manipulation to actuate cell and drug delivery utilizing AC electrokinetic -powered microswimmer

Bioparticle trapping and transporting are essential processes for developing an integrated cell and drug delivery system. Herein, we present a unique platform that effectively combines magnetic field and alternating current (AC) electrokinetics for the simultaneous manipulation of bioparticles across scales. The magnetic field is used to control the moving direction of Janus swimmers, and the AC electrokinetics incorporating dielectrophoresis (DEP) and induced charge electroosmosis (ICEO) flow are utilized to power Janus swimmers to manipulate bioparticles. Numerical characterization of the stagnant regions generated by DEP and ICEO elucidates the trapping mechanisms for both micro and nano bioparticles. We demonstrate that the Janus swimmers are capable of navigating along varied trajectories at speeds of up to hundreds of micrometers per second. Developed phase maps, derived from AC frequency and medium conductivity parameters, delineate three distinct bioparticle loading positions, offering a versatile guide for the manipulation of cells and nanodrugs. The platform’s adaptability is further highlighted by its success in performing mobile trapping of cells and nanodrugs along user-defined trajectories, targeted trapping of nanoparticle aggregations, and simultaneous multi-scale bioparticle capture. The presented multi-scale bioparticle trapping strategy, together with its unique features of simple geometric configuration, facile operation and broad applicability, can broaden utility in cellular and pharmaceutical research.

Effect of electroosmosis flow and electrolyte circulation on electrokinetic remediation of Pb-contaminated kaolin

Effect of electroosmosis flow and electrolyte circulation on electrokinetic remediation of Pb-contaminated kaolin

Electro osmotic flow of nanofluids within a porous symmetric tapered ciliated channel

AbstractIn this investigation, a comprehensive study has been made to reveal electro osmosis flow through a tapered ciliated symmetric porous channel. The flow is initiated due to metachronal dynamics of cilia. Axial electric field is deployed and thermal radiation phenomenon is scrutinised by applying convective conditions. The equations tackling the flow are non dimensionalized and simplified by capitalizing the low Reynolds number and long wave length approximations. Analytical solution is presented for well reputed Poissson equation and the axial velocity. Whereas, traverse velocity, temperature and nanofluids concentration profiles are examined numerically in MATHEMATICA. Variation of emerging crucial parameters on the velocity profile, temperature and concentration profiles, pressure gradient, pressure rise per wavelength, and on the velocity distribution inside the micro ciliated are exhibited with the aid of graphical deliberations. It worth to mention in this work that in case of tapered channel transverse velocity also has significant contribution in the flow, which is observed trivial in symmetric and non‐symmetric channel flows. Temperature of the nanofluid in the ciliated tapered channel is raised with permeability and thermal radiations phenomena and can be controlled with Helmholtz Smoluchowski velocity, and electroosmotic parameter. Pumping phenomena is affected with increase in Helmholtz Smoluchowski velocity and permeability. Reported investigation cover a informative insight about biological fluid system, may be beneficial for the understanding the flow through ductus efferentes of human reproductive tract since it assumed that cilia are responsible for the transport of sperm from rete testis to the epididymis, also have worth in cilia designed bio‐sensors and in certain drug delivery systems.

Effects of Electroosmosis Flow of Bingham Plastic Fluid Induced by a Curved Microtube

Effects of Electroosmosis Flow of Bingham Plastic Fluid Induced by a Curved Microtube

Unraveling the transformative impact of ternary hybrid nanoparticles on overlapped stenosis with electroosmotic vascular flow kinetics and heat transfer

This study examines how ternary hybrid nanoparticles affect electroosmotic vascular flow kinetics and heat transfer. Through a meticulous exploration of their intricate interplay, this research unveils unprecedented insights into their transformative impact. By comprehensively analyzing the dynamics of vascular flow and thermal behavior under the influence of ternary hybrid nanoparticles, novel advancements are revealed. The assessment is innovative because it incorporates electroosmotic force on blood flow that contains three different nanoparticles (Ti O2, Al2O3 and Si O2). To evaluate the numerical solution, an unraveled approach using the finite element method is employed, ensuring both stability and convergence of the solution. The computed numerical results are presented in graphs and tables, showcasing the relationship between key factors. The comparative analysis uncovers the unparalleled performance and remarkable efficacy of these nanoparticles in enhancing the electroosmotic vascular flow and optimizing heat transfer. The electric field due to the electroosmosis flow interacts with flow pattern and influence the potential flow and vortex formation. This research presents a paradigm shift in the understanding of biomedical engineering and fluid dynamics, offering promising prospects for revolutionizing healthcare technologies and achieving unprecedented levels of thermal management efficiency across diverse applications.

Interplay of electrokinetic effects in nonpolar solvents for electronic paper displays

HypothesisElectronic paper displays rely on electrokinetic effects in nonpolar solvents to drive the displacement of colloidal particles within a fluidic cell. While Electrophoresis (EP) is a well-established and frequently employed phenomenon, electro-osmosis (EO), which drives fluid flow along charged solid surfaces, has not been studied as extensively. We hypothesize that by exploiting the interplay between these effects, an enhanced particle transport can be achieved. ExperimentsIn this study, we experimentally investigate the combined effects of EP and EO for colloidal particles in non-polar solvents, driven by an electric field. We use astigmatism micro-particle tracking velocimetry (A-μPTV) to measure the motion of charged particles within model fluidic cells. Using a simple approach that relies on basic fluid flow properties we extract the contributions due to EP and EO, finding that EO contributes significantly to particle transport. The validity of our approach is confirmed by measurements on particles with different magnitudes of charge, and by comparison to numerical simulations. FindingsWe find that EO flows can play a dominant role in the transport of particles in electrokinetic display devices. This can be exploited to speed up particle transport, potentially yielding displays with significantly faster switching times.

Controllable and Scaffold‐Free Formation of 3D Multicellular Architectures Using a Bipolar Electrode Array

AbstractThe natural environment of cells in vivo is a 3D network in which cellular responses are determined by influences from surrounding cells on all sides. This complex system is hard to be recapitulated in a conventional way. It is highly desirable to replace 2D models with 3D cell culture models. Microfluidic technology offers a variety of advantageous approaches for the long‐term 3D cell culture. Herein, a new cell patterning approach for generating cell clusters of specified size and shape by exploiting induced charge electroosmosis (ICEO) flow at a bipolar electrode array is exploited. Cell or particle clusters can be produced at the edges or centers of bipolar electrodes (BPEs) with controlled organization, by designing electrodes with arbitrary shapes. This platform is further extended to flexibly organize biological units with different properties via the ICEO or dielectrophoresis (DEP) based assembly. Heterotypic cell clusters can be produced at the bipolar electrode (BPE) by adjusting the applied frequencies and the sample injection sequence. This hybrid approach by integrating ICEO flow vortexes and DEP properties of the cells, allows the wireless generation of high‐throughput 3D clusters or spheroids with size adjustability and biocompatibility, which shows great potential in tissue engineering, drug discovery, and tumor research.

A numerical study on applying ion concentration polarization in micropump design

This work focuses on applying the phenomenon of ion concentration polarization to design and investigate a micropump model that is a kind of electroosmotic micropump. Numerical study is conducted for ion concentration polarization in the manner that generates electro-osmosis flow and pumping effect. The formation of the extended space charge layer and the actions of the electric field upon this layer is applied to generate electro-osmosis flow to drive flow in the system. It is clarified that pumping effect can be enhanced by improving the geometry configurations. Multiple simulations are conducted to obtain an optimal micropump design.

Transdermal drug delivery using a porous microneedle device driven by a hydrogel electroosmotic pump.

Integrating a hydrogel electroosmotic pump with a parylene C-coated porous microneedle (PMN) is developed for transdermal drug delivery applications. The hydrogel pump is fabricated by combining an anionic and a cationic hydrogel to generate enhanced electroosmosis flow (EOF) to drive the transportation of molecules via PMN.

Theoretical study of silver nanoparticle suspension in electroosmosis flow through a nonuniform divergent channel with compliant walls: A therapeutic application

This study explores the effect of silver nanoparticles on heat transfer and flow behavior within the context of the Ellis fluid model. It specifically considers electroosmotic forces in a nonuniform divergent channel with compliant walls. The analysis involves studying thermal transport in silver-blood nanofluid flow, using MATHEMATICA 13.2 software to obtain exact solutions for velocity and temperature distribution. Findings reveal that certain parameters, such as wall damping and wall elastic properties, increase skin friction, while compliant wall parameters generally reduce flow velocity. Additionally, wall rigidity and tension parameters lead to larger trapped boluses. Notably, a 1% concentration of nanoparticles enhances heat transfer by up to 13.75%, offering control over heat transfer rates. This research introduces a novel perspective by examining compliant wall impacts on heat transfer analysis in the context of electroosmotic flow within the Ellis fluid model, incorporating silver nanoparticles with potential therapeutic applications due to their antibacterial properties.

Influence of remediation by electrokinetic on the chemical and geotechnical properties of clayey soil contaminated by copper sulfate

The enhanced electrokinetic (EK) technique is an innovative approach and increasingly used in remediation of the fine-grained texture soils contaminated with different types of contaminant. In this study, the EK is enhanced by adding an intermediate compartment and using purging solutions at the electrode’s compartments. The natural clayey soil samples were obtained from Al-Ahadab oil field and artificially contaminated with two ratios of copper sulfate (66666.67 and 26666.67 mg/kg). The feasibility of using EK technique was evaluated by the efficiency of extracting copper from soil and the magnitude of recovery in the geotechnical properties of soil. The duration of remediation was continued for about 240-250 hours depending either on the continuity of electroosmosis flow or reach a constant rate of electrical current. The removal efficiency of copper from contaminated soil samples was ranged from 98.4% to 99.6%. The EK remediation technique proved a marginal impact on the specific gravity and Atterberg’s limits, but it has a significant effect on the shear strength parameters and compressibility of soil. Furthermore, the EK technique can be considered an efficient method for removing the low and high concentrations of copper sulfate from clayey soil of low permeability.

Induced-charge electroosmosis flow of viscoelastic fluids under different voltage arrangements

Efficient mixing of chemical analysis reagents with laboratory samples at a microscale is a key issue in numerous biomedical and chemical analyses but hardly to implement due to the limited of the low diffusivity in laminar flow. Induced-charge electroosmosis flow, as an innovative mixing method, has been proved to be effective and simple in rapid mixing attributes to its mechanism of vortex generation. This work aims to propose a new strategy for chaotic induced-charge electroosmosis flow based on different voltage arrangements to improve the mixing of viscoelastic fluids. The Phan–Thien–Tanner constitutive model is applied to characterize the flow behavior of viscoelastic fluid in a microfluidic preparation mixer. The direct numerical simulation method is used to solve the fully coupled Navier–Stokes and Poisson–Nernst–Planck equations for a polarizable cylinder in a two-dimensional cavity filled with electrolyte solution. The impact of Weissenberg number (Wi), Debye parameter, voltage strength on the velocity, net charge density, and potential profiles is investigated. The simulation results indicate that a greater Wi leads to the decrease in the maximum velocity, and a large voltage strength can heighten the net charge density and potential, thus improve the peak velocity. Moreover, the classical theoretical prediction that the maximum velocity is proportional to the square of the applied voltage has been authenticated.

Rotation, electromagnetic field, and variable thermal conductivity effects on free convection flow past an eternity vertical porous plate

AbstractThe present research may facilitate the reduction of the number of conversion steps required to include the low output voltages in an electrokinetic biomass process. Variable thermal conductivity and electroosmosis flow have already established great potential in the thermo‐elastic models of various manufacturing industries and have been widely used in energy technologies. As a result, the current framework investigates the characteristics of natural convection flow with the influence of variable thermal conductivity and electroosmosis over an eternity vertical porous plate. Coriolis forces and Hall current effects are considered in the momentum equations, and also thermal radiation and variable thermal conductivity are taken as energy equations. A linear chemical reaction parameter is used in the concentration equation. The equation of Poisson–Boltzmann is exploited to depict the electric potential characteristics within the accelerated plate medium. The pdepe command in Matlab software is used to figure out the numerical solutions to equations about momentum, energy, and concentration. The expressions of fluid transverse velocity, fluid axial velocity, fluid temperature, and concentration profiles are presented as numerical results and also derived vital relevant stream parameters diagrammatically, whereas the numerical values of primary skin friction, secondary skin friction, and Nusselt number are presented in tabular form for various values of pertinent flow parameters. The temperature rises as the strength of the thermal conductivity variable parameter increases. Also, as the values of the Taylor number and the thermal conductivity variable parameter go up, the primary velocity goes down. Similarly, secondary velocity increases in the opposite direction as the Taylor number and thermal conductivity variable parameter increase.

Calculation of electro-osmotic flow development length in a rotating three-dimensional microchannel

The numerical modeling of an electroosmosis flow in a rectangular three-dimensional rotating microchannel has been studied. The study’s goal is to calculate the flow’s development length, and as a novelty, a correlation is proposed to estimate the development length. The flow was simulated for angular velocity (ω) ranges of 0–9 and electric potential (φ) ranges of 0.1–0.3. The results were imported into the curve fitting toolbox to determine a correlation for the development length. The correlation was obtained as a function of angular velocity, electric potential, and hydraulic diameter. The results show that increasing both ω and φ leads to an increase in flow development length, where for constant φ, increasing ω from 0 to 9 results in a 20%–30% increase in development length. Furthermore, increasing φ from 0.1 to 0.3 for a constant ω raises development length by 35%–50%. The velocity field and its parameters, such as ω and φ, were analyzed and discussed.

Back Cover: Efficient nanoparticle focusing utilizing cascade AC electroosmotic flow

DOI: 10.1002/elps.202200054 The cover picture shows continuous focusing of nanoscale samples using a cascade AC electroosmosis (cACEO) flow. ACEO flow is produced by applying AC signal to the coplanar integrated electrode. The cascade electrode, combining chevron and double-gap geometry, was developed to perform efficient 3D nanoparticle focusing. Chevron electrode was used to generate inward flow from the sidewall to the center area to accumulate particles from the scattering area; then, the DG electrode provides the necessary ACEO to concentrate nanoparticles. The study shows that the cACEO concentrator holds significant potential to concentrate nanoscale samples, such as particles, rare samples, and biomaterials.

Efficient nanoparticle focusing utilizing cascade AC electroosmotic flow.

This study presents on‐chip continuous accumulation and concentration of nanoscale samples using a cascade alternating current electroosmosis (cACEO) flow. ACEO can generate flow motion caused by ion movement due to interactions between the AC electric field and the induced charge layer on the electrode surface, with the potential to accumulate particles, especially in low‐conductive liquid. However, the intrinsic particle diffusive motion, which is sensitive to particle size, is an essential element influencing accumulation efficiency. In this study, an electrode combining chevron and double‐gap geometry embedded in a microfluidic channel was developed to perform efficient three‐dimensional (3D) nanoparticle focusing using ACEO. The chevron electrode pattern was introduced upstream of the focusing zone to overcome particle accumulation in scattering zones near the channel sidewall. To demonstrate the efficiency of the proposed device for particle accumulation, three nanoparticle types were used: latex, metal, and biomaterial. Continuous 3D concentration of 50‐nm polystyrene particles was confirmed. The concentration factor, determined based on image processing, became quite high when 50‐nm gold nanoparticles were used. Moreover, nanoparticles with a 20‐nm diameter were accumulated using cACEO. Finally, we used the concentrator chip to accumulate 50‐nm liposome particles, confirming that the device could also successfully concentrate biomaterials.

Analytical Model of Electroosmosis and Ion Transport Flow in Nanofluid Channel

Analytical Model of Electroosmosis and Ion Transport Flow in Nanofluid Channel

Interplay of induced charge electroosmosis and electrothermal flow in insulator-based dielectrophoresis

A depth-averaged numerical model is developed to understand the experimentally observed interplay of induced charge electroosmosis and electrothermal flow in an insulator-based dielectrophoresis microdevice. The experimentally measured nonlinear fluid velocity matches asymptotically the predicted velocity of the electroosmotic flow in a low-concentration buffer and that of electrothermal flow in a high-concentration buffer. This agreement is consistent with a scaling analysis.