Microfluidic Continuous Particle Separation via AC-Dielectrophoresis With 3D Electrodes

2008 ◽  
Author(s):  
Barbaros C¸etin ◽  
Dongqing Li
Keyword(s):  
Numerical Simulation ◽  
Electric Field ◽  
Electric Field Gradient ◽  
Pressure Difference ◽  
Rectangular Channel ◽  
Particle Separation ◽  
Main Flow ◽  
Uniform Electric Field ◽  
3D Electrodes ◽  
Continuous Particle

In this paper, we are presenting the numerical simulation of a novel, simple microfluidic device for continuous separation of the particles according to their size. The device is composed of a straight rectangular channel connecting two inlet reservoirs to two exit reservoirs. Two asymmetric, straight, 3D electrodes are embedded inside the channel along the wall to create a non-uniform electric field for the DEP separation. The separated particles are collected at the different exit reservoirs. Main flow is induced by the pressure difference between the inlet and the exit reservoirs. The region affected by the electric field gradient is confined within the vicinity of the electrodes. Therefore, the undesired effects of the electric field on the system are minimized.

Numerical Simulation of Dielectrophoretic Particle Separation

2018 ◽  
Author(s):  
B. Kazemi ◽  
J. Darabi
Keyword(s):  
Numerical Simulation ◽  
Electric Field ◽  
Open Source Software ◽  
Fluid Transport ◽  
Microfluidic Channel ◽  
Particle Separation ◽  
Repulsive Force ◽  
Uniform Electric Field ◽  
Computational Domain ◽  
Simulation And Optimization

This study presents the numerical simulation and optimization of a dielectrophoretic bio-separation chip for isolating bioparticles such as circulating tumor cells (CTCs). The chip consists of ten pairs of electrodes placed with an angle of 10° with respect to the direction of the flow on the top and bottom walls of the channel. The spatially non-uniform electric field produced by the slanted electrodes applies a repulsive force on the particles that are flowing through the channel. The repulsive force applied by the top and bottom electrodes are balanced and the particles flow along the centerline of the channel. On the other hand, the magnitude of forces resulted from electric field in the x and z-directions deflects particles depending on their size and guides them towards different outlets. Numerical simulation of the particle-fluid transport was performed using an open-source software named OpenFOAM and the deflection of the particles within the microfluidic channel was predicted. The present computational domain considers the dominant forces such as dielectrophoretic and hydrodynamic forces as well as their effects on the design and operating parameters of the chip. The results show that this device is capable of separating various cells based on their size.

scholarly journals Continuous Particle Separation Driven by 3D Ag-PDMS Electrodes with Dielectric Electrophoretic Force Coupled with Inertia Force

Micromachines ◽  
2022 ◽  
Vol 13 (1) ◽  
pp. 117
Author(s):  
Xiaohong Li ◽  
Junping Duan ◽  
Zeng Qu ◽  
Jiayun Wang ◽  
Miaomiao Ji ◽  
...  
Keyword(s):  
Electric Field ◽  
Particle Separation ◽  
Silica Particles ◽  
Uniform Electric Field ◽  
Inertia Force ◽  
New Approach ◽  
Field Distributions ◽  
Novel Approach ◽  
3D Electrodes ◽  
Biological And Medical Applications

Cell separation has become @important in biological and medical applications. Dielectrophoresis (DEP) is widely used due to the advantages it offers, such as the lack of a requirement for biological markers and the fact that it involves no damage to cells or particles. This study aimed to report a novel approach combining 3D sidewall electrodes and contraction/expansion (CEA) structures to separate three kinds of particles with different sizes or dielectric properties continuously. The separation was achieved through the interaction between electrophoretic forces and inertia forces. The CEA channel was capable of sorting particles with different sizes due to inertial forces, and also enhanced the nonuniformity of the electric field. The 3D electrodes generated a non-uniform electric field at the same height as the channels, which increased the action range of the DEP force. Finite element simulations using the commercial software, COMSOL Multiphysics 5.4, were performed to determine the flow field distributions, electric field distributions, and particle trajectories. The separation experiments were assessed by separating 4 µm polystyrene (PS) particles from 20 µm PS particles at different flow rates by experiencing positive and negative DEP. Subsequently, the sorting performances of the 4 µm PS particles, 20 µm PS particles, and 4 µm silica particles with different solution conductivities were observed. Both the numerical simulations and the practical particle separation displayed high separating efficiency (separation of 4 µm PS particles, 94.2%; separation of 20 µm PS particles, 92.1%; separation of 4 µm Silica particles, 95.3%). The proposed approach is expected to open a new approach to cell sorting and separating.

Effects of Electrode Configurations on Internal Stress Distribution of Multilayer Actuators

2003 ◽  
Vol 785 ◽  
Author(s):  
Dong-Kyun Lee ◽  
Ji-Won Choi ◽  
Deuk-Young Han ◽  
Hyun-Jai Kim ◽  
Seok-Jin Yoon
Keyword(s):  
Numerical Simulation ◽  
Stress Concentration ◽  
Stress Distribution ◽  
Electric Field ◽  
Internal Stress ◽  
Uniform Electric Field ◽  
Multilayer Actuator ◽  
Multilayer Actuators

ABSTRACTThe internal stress distribution in multilayer actuator was analyzed by a numerical simulation. Around the edge of conventional inter-digital electrodes, the non-uniform electric field generated the stress concentration, which caused the ceramic to crack. Various electrode configurations were presented to decrease this stress concentration. Especially the float electrode type is a promising design because this can be fabricated using almost the same process as the conventional multilayer actuator, and the simulated results indicted that the float electrode type decreased the stress concentration of inter-digital type in approximately 1/3.

Dielectrophoretic Separation Motion of a Particle From Electrolyte Solution in Micro-Channel

2007 ◽  
Author(s):  
Zhenqian Chen ◽  
Mingheng Shi
Keyword(s):  
Electric Field ◽  
Spherical Particle ◽  
Electrolyte Solution ◽  
Particle Separation ◽  
Viscous Friction ◽  
Gravitational Effect ◽  
Separation Distance ◽  
Uniform Electric Field ◽  
Micro Channel ◽  
Viscous Friction Force

Dielectrophoresis (DEP) based on the processes of particle separation and particle detection in micro-channel is one of the most important operations required for many lab-on-a-chip devices. To understand the mechanism of the DEP, a theoretical analysis of dielectrophoretic separation motion of a spherical particle in a rectangular micro-channel filled with an aqueous electrolyte solution is presented in this paper. The dimensions of micro-channel are 100 μm in width and 200 μm in length. In this study, driven forces on the particle are analyzed in detail. At the gravitational direction, it is assumed that the density of the spherical particle is higher than that of the solution, and thus the gravitational effect is considered coupled with the buoyancy force and the electric double layer interaction force as well as the van der Waals force. Both the DEP force and the viscous friction force drive the particle separation motion from the solution in micro-channel. The particle separation distance of the particle from the bottom wall by the action of these forces and its motion behavior are analyzed and calculated. The DEP motion along the channel in an applied non-uniform electric field is simulated. Effects of particle’s size, electrolyte solution concentration and applied electric field strength on the DEP motion are discussed.

scholarly journals Numerical simulation of an uncharged droplet in a uniform electric field

2006 ◽  
Vol 64 (7-9) ◽  
pp. 562-568 ◽  
Author(s):  
Adel M. Benselama ◽  
Jean-Luc Achard ◽  
Pascale Pham
Keyword(s):  
Numerical Simulation ◽  
Electric Field ◽  
Uniform Electric Field

Microfluidic MEMS Device in the Cultivation of Microalgae With Positive Dielectrophoretic Cell Trapping for Media Exchange

2014 ◽  
Author(s):  
Johnson J. Wong ◽  
Emil Geiger
Keyword(s):  
Electric Field ◽  
Electric Field Gradient ◽  
Field Gradient ◽  
Microfluidic Device ◽  
Cell Manipulation ◽  
Regular Growth ◽  
Uniform Electric Field ◽  
Growth Media ◽  
Cell Trapping ◽  
Mems Device

Through COMSOL modeling and electrode design, positive dielectrophoretic (pDEP) cell trapping for media exchange has been demonstrated on live Chlamydomnas reinhardtii in regular growth medium in a PDMS-glass microfluidic MEMS device. Dielectrophoresis (DEP) is the force applied to dielectric particles in an alternating current (AC) non-uniform electric field. A DEP force toward the increasing electric field gradient is called positive (pDEP). There are several published DEP structures for various applications such as: simple interdigitated structures for particle sorting in flow, DEP tweezers for single cell manipulation, and spiral structures for general cell manipulation. pDEP trapping over large areas (area pDEP) has been demonstrated with the use of low conductivity suspending media, but for higher conductivity suspending media, such as growth media, the pDEP force is reduced, and less likely to trap and hold microalgae against the hydrodynamic forces during media exchange. Multiphysics software, COMSOL, was used to model repeating structures suited for trapping of cells over the bottom area of a microfluidic device, which is useful and necessary for media exchange of a cell culture in a simple microfluidic device. The theoretical model of dielectrophoretic (DEP) force on a homogenous sphere in a homogenous medium in an electric field is a function of the sphere radius and conductivity, medium permittivity, and the gradient of the electric field. By assuming the conductivities, permittivities, and the particle geometry remains constant, the gradient of the electric field is the determining factor for the strength of the pDEP force. Modeling the electric fields and the resulting electric field gradient of various interdigitated electrode configurations allowed for the optimization of an electrode structure’s area of higher electric field gradients. The completed microfluidic device consisted of a single channel and a wide growth chamber overlaid over patterned gold-chrome electrodes. The MEMS device was fabricated using soft lithography and photolithography on the etched chrome-gold glass slides. The pDEP trapping was successful in trapping C. reinhardtii for media exchange. Media exchange allows for nutrient replenishment and waste removal, allowing for control of the growth conditions.

Sign in / Sign up

Export Citation Format

Share Document