scholarly journals Stretching DNA by electric field and flow field in microfluidic devices: An experimental validation to the devices designed with computer simulations

2013 ◽  
Vol 7 (1) ◽  
pp. 014109 ◽  
Author(s):  
Cheng-Han Lee ◽  
Chih-Chen Hsieh
Keyword(s):  
Flow Field ◽  
Electric Field ◽  
Computer Simulations ◽  
Experimental Validation ◽  
Microfluidic Devices

Numerical Simulation on the Electrophoretic Motion of Multiple Particles in Microchannels

2004 ◽  
Author(s):  
Chunzhen Ye ◽  
Dongqing Li
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Electric Field ◽  
Particle Motion ◽  
Outer Region ◽  
Numerical Results ◽  
The Other ◽  
Double Layers ◽  
Rectangular Microchannel ◽  
Moving Particle

This paper considers the electrophoretic motion of multiple spheres in an aqueous electrolyte solution in a straight rectangular microchannel, where the size of the channel is close to that of the particles. This is a complicated 3-D transient process where the electric field, the flow field and the particle motion are coupled together. The objective is to numerically investigate how one particle influences the electric field and the flow field surrounding the other particle and the particle moving velocity. It is also aimed to investigate and demonstrate that the effects of particle size and electrokinetic properties on particle moving velocity. Under the assumption of thin electrical double layers, the electroosmotic flow velocity is used to describe the flow in the inner region. The model governing the electric field and the flow field in the outer region and the particle motion is developed. A direct numerical simulation method using the finite element method is adopted to solve the model. The numerical results show that the presence of one particle influences the electric field and the flow field adjacent to the other particle and the particle motion, and that this influences weaken when the separation distance becomes bigger. The particle motion is dependent on its size, with the smaller particle moving a little faster. In addition, the zeta potential of particle has an effective influence on the particle motion. For a faster particle moving from behind a slower one, numerical results show that the faster moving particle will climb and then pass the slower moving particle then two particles’ centers are not located on a line parallel to the electric field.

Numerical Study on Electrokinetic Interaction Between a Pair of Cylindrical Colloidal Particles

2009 ◽  
Author(s):  
Dolfred Vijay Fernandes ◽  
Sangmo Kang ◽  
Yong Kweon Suh
Keyword(s):  
Flow Field ◽  
Electric Field ◽  
Colloidal Particles ◽  
Stokes Equations ◽  
Separation Efficiency ◽  
Numerical Study ◽  
Interaction Force ◽  
Surface Element ◽  
Immersed Boundary ◽  
Interaction Forces

Electrophoresis is the motion of dispersed particles relative to a fluid under the influence of an electric field. Presently this phenomenon of electrokinetics is widely used in biotechnology for the separation of proteins, sequencing of polypeptide chains etc. The separation efficiency of these biomolecules is affected by their aggregation. Thus it is important to study the interaction forces between the molecules. In this study we calculate the electrophoretic motion of a pair of colloidal particles under axial electric field. The hydrodynamic and electric double layer (EDL) interaction forces are calculated numerically. The EDL interaction force is calculated from electric field distribution around the particle using Maxwell stress tensor and the hydrodynamic force is calculated from the flow field obtained from the solution of Stokes equations. The continuous forcing approach of immersed boundary method is used to obtain flow field around the moving particles. The EDL distribution around the particles is obtained by solving Poisson-Nernst-Planck (PNP) equations on a hybrid grid system. The EDL interaction force calculated from numerical solution is compared with the one obtained from surface element integration (SEI) method.

AC electric field controlled non-Newtonian filament thinning and droplet formation on the microscale

Lab on a Chip ◽  
2017 ◽  
Vol 17 (17) ◽  
pp. 2969-2981 ◽  
Author(s):  
Y. Huang ◽  
Y. L. Wang ◽  
T. N. Wong
Keyword(s):  
Flow Field ◽  
Electric Field ◽  
Newtonian Fluid ◽  
High Speed ◽  
Droplet Formation ◽  
Particle Imaging Velocimetry ◽  
Ac Electric Field ◽  
Formation Dynamics ◽  
Particle Imaging ◽  
First Time

We investigate the AC electric field controlled filament thinning and droplet formation dynamics of one non-Newtonian fluid. Furthermore, for the first time, we quantitatively measure the flow field of the non-Newtonian droplet formation under the influence of AC electric field, via a high-speed micro particle imaging velocimetry (μPIV) system. We discover the viscoelasticity contributes to the discrepancies majorly.

Computer Simulations of Electrokinetic Injection Techniques in Microfluidic Devices

2000 ◽  
Vol 72 (15) ◽  
pp. 3512-3517 ◽  
Author(s):  
Sergey V. Ermakov ◽  
Stephen C. Jacobson ◽  
J. Michael Ramsey
Keyword(s):  
Computer Simulations ◽  
Microfluidic Devices ◽  
Electrokinetic Injection ◽  
Injection Techniques

Control of Flow Field, Mass Transfer and Mixing Enhancement in T-Shaped Microchannels

2016 ◽  
Vol 33 (3) ◽  
pp. 387-394
Author(s):  
Y. Bazargan-Lari ◽  
S. Movahed ◽  
M. Mashhoodi
Keyword(s):  
Flow Field ◽  
Applied Voltage ◽  
Electroosmotic Flow ◽  
Microfluidic Devices ◽  
Mixing Efficiency ◽  
Mixing Enhancement ◽  
Field Mass ◽  
Control Of Flow ◽  
Micro Mixer ◽  
Two Fluid

AbstractA T-shaped microfluidic micro-mixer was designed to mix desired concentrations of two fluid streams and to prepare their homogenous mixture solution. A hydrostatic pressure gradient was induced in one of the branches of the system (mixing channel) by applying external electric field and generating electroosmotic flow in the two other branches of the system. The flow field and transferred mass into the mixing channel can be regulated by controlling the applied voltage of the system. In order to prepare more homogenous mixture solution, some obstacles were added to the mixing channel to induce perturbation in the flow field and enhance the mixing efficiency of the system. Numerical simulations were performed to show the correctness of the proposed mixing strategy and to investigate the influences of the applied voltage on the mixing efficiency and induced pressure flow in the mixing channel. A proposed design can be used as a guideline to control and enhance mixing efficiency, and consequently functionality, of different microfluidic devices.

scholarly journals Electrotaxis of oral squamous cell carcinoma cells in a multiple-electric-field chip with uniform flow field

2012 ◽  
Vol 6 (3) ◽  
pp. 034116 ◽  
Author(s):  
Hsieh-Fu Tsai ◽  
Shih-Wei Peng ◽  
Chun-Ying Wu ◽  
Hui-Fang Chang ◽  
Ji-Yen Cheng
Keyword(s):  
Squamous Cell Carcinoma ◽  
Oral Squamous Cell Carcinoma ◽  
Flow Field ◽  
Electric Field ◽  
Cell Carcinoma ◽  
Squamous Cell ◽  
Uniform Flow ◽  
Carcinoma Cells

On fluid motions induced by an electromagnetic field in a liquid drop immersed in a conducting fluid

1972 ◽  
Vol 51 (3) ◽  
pp. 585-591 ◽  
Author(s):  
C. Sozou
Keyword(s):  
Magnetic Field ◽  
Electromagnetic Field ◽  
Flow Field ◽  
Electric Field ◽  
Lorentz Force ◽  
Liquid Drop ◽  
Conducting Fluid ◽  
Uniform Electric Field ◽  
Tangential Electric Field ◽  
Set Up

The deformation of a liquid drop immersed in a conducting fluid by the imposition of a uniform electric field is investigated. The flow field set up is due to the surface charge and the tangential electric field stress over the surface of the drop, and the rotationality of the Lorentz force which is set up by the electric current and the associated magnetic field. It is shown that when the fluids are poor conductors and good dielectrics the effects of the Lorentz force are minimal and the flow field is due to the stresses of the electric field tangential to the surface of the drop, in agreement with other authors. When, however, the fluids are highly conducting and poor dielectrics the effects of the Lorentz force may be predominant, especially for larger drops.

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