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 ◽  
...  

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.

Author(s):  
Barbaros C¸etin ◽  
Dongqing Li

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.


Author(s):  
Zhenqian Chen ◽  
Mingheng Shi

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.


Author(s):  
B. Kazemi ◽  
J. Darabi

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.


1997 ◽  
Vol 487 ◽  
Author(s):  
H. W. Yao ◽  
R. J. Anderson ◽  
R. B. James ◽  
R. W. Olsen

AbstractThe internal electric field distributions of the CdZnTe (CZT) detectors under bias were characterized by optical polarized transmission at a 952 nm illumination utilizing the Pockels electro-optic effect. Two-dimensional (2D) images mapping the internal electrical field intensity changes were obtained to study the performance of CZT room-temperature radiation detectors. Planar and a P-I-N structured CZT detectors were investigated under different operating bias voltages. Analysis of optical profiles from a planar single crystal detector provides a quantitative nondestructive description of the electric field or voltage distributions inside a radiation detector. The P-I-N structured CZT detector showed a nearly uniform electric field in a width which varied with the operating bias voltage. An energyband model of a semiconductor junction with a depletion layer was employed to understand the results.


1997 ◽  
Vol 117 (11) ◽  
pp. 1109-1114
Author(s):  
Yoshiyuki Suda ◽  
Kenji Mutoh ◽  
Yosuke Sakai ◽  
Kiyotaka Matsuura ◽  
Norio Homma

2008 ◽  
Vol 128 (12) ◽  
pp. 1445-1451
Author(s):  
Takanori Yasuoka ◽  
Tomohiro Kato ◽  
Katsumi Kato ◽  
Hitoshi Okubo

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