M805 Numerical Analysis on Electroosmotic Flow in Changing Direction of Applied Electric Field

2016 ◽  
Vol 2016.91 (0) ◽  
pp. 339
Author(s):  
Hidetoshi HASHIMOTO ◽  
Hiroshige KUMAMARU
Keyword(s):  
Numerical Analysis ◽  
Electric Field ◽  
Applied Electric Field ◽  
Electroosmotic Flow

Synergistic use of electroosmotic flow and magnetic forces for nucleic acid extraction

The Analyst ◽  
2020 ◽  
Vol 145 (6) ◽  
pp. 2412-2419 ◽  
Author(s):  
Rachel N. Deraney ◽  
Lindsay Schneider ◽  
Anubhav Tripathi
Keyword(s):  
Nucleic Acid ◽  
Electric Field ◽  
Microfluidic Chip ◽  
Applied Electric Field ◽  
Electroosmotic Flow ◽  
Acid Extraction ◽  
Nucleic Acid Extraction ◽  
Magnetic Forces ◽  
Extraction And Purification

NA extraction and purification utilitzing a microfluidic chip with applied electric field to induce electroosmotic flow opposite the magnetic NA-bound bead mix.

Two-Fluid Electroosmotic Flow in Microchannels

2008 ◽  
Author(s):  
T. N. Wong ◽  
Y. Gao ◽  
C. Wang ◽  
C. Yang ◽  
N. T. Nguyen ◽  
...  
Keyword(s):  
Electric Field ◽  
Applied Electric Field ◽  
Electroosmotic Flow ◽  
Viscosity Ratio ◽  
Experimental Investigations ◽  
Fluid Interface ◽  
Surface Charges ◽  
Interface Position ◽  
Proposed Model ◽  
Two Fluid

This paper presents theoretical and experimental investigations of the pressure-driven two-liquid flow in microchannels with the electroosmosis effect. For a fully developed, steady state, laminar flow of two liquids combined the pressure gradient, electroosmosis and surface charges at the liquid-liquid interface, we have derived analytical solutions that relate the velocity profiles and flow rates to the liquid holdup, the aspect ratio of the microchannel, the viscosity ratio of the two liquids and the externally applied electric field. It was shown that adjusting the externally applied electric field could control the fluid interface position precisely. The prediction from the proposed model compares very well with measured data.

scholarly journals Electroosmotic Flow of Viscoelastic Fluid through a Constriction Microchannel

Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 417
Author(s):  
Jianyu Ji ◽  
Shizhi Qian ◽  
Zhaohui Liu
Keyword(s):  
Electric Field ◽  
Newtonian Fluid ◽  
Viscoelastic Fluid ◽  
Apparent Viscosity ◽  
Applied Electric Field ◽  
Electroosmotic Flow ◽  
Microfluidic Channel ◽  
Critical Value ◽  
Poisson Boltzmann ◽  
Boltzmann Model

Electroosmotic flow (EOF) has been widely used in various biochemical microfluidic applications, many of which use viscoelastic non-Newtonian fluid. This study numerically investigates the EOF of viscoelastic fluid through a 10:1 constriction microfluidic channel connecting two reservoirs on either side. The flow is modelled by the Oldroyd-B (OB) model coupled with the Poisson–Boltzmann model. EOF of polyacrylamide (PAA) solution is studied as a function of the PAA concentration and the applied electric field. In contrast to steady EOF of Newtonian fluid, the EOF of PAA solution becomes unstable when the applied electric field (PAA concentration) exceeds a critical value for a fixed PAA concentration (electric field), and vortices form at the upstream of the constriction. EOF velocity of viscoelastic fluid becomes spatially and temporally dependent, and the velocity at the exit of the constriction microchannel is much higher than that at its entrance, which is in qualitative agreement with experimental observation from the literature. Under the same apparent viscosity, the time-averaged velocity of the viscoelastic fluid is lower than that of the Newtonian fluid.

scholarly journals Numerical Investigation of Nanostructure Orientation on Electroosmotic Flow

Micromachines ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 971
Author(s):  
An Eng Lim ◽  
Yee Cheong Lam
Keyword(s):  
Electric Field ◽  
Field Distribution ◽  
Applied Electric Field ◽  
Electroosmotic Flow ◽  
Electric Field Distribution ◽  
Flow Direction ◽  
Fluid Velocity ◽  
Orientation Angle ◽  
Dependent Behavior ◽  
Velocity Region

Electroosmotic flow (EOF) is fluid flow induced by an applied electric field, which has been widely employed in various micro-/nanofluidic applications. Past investigations have revealed that the presence of nanostructures in microchannel reduces EOF. Hitherto, the angle-dependent behavior of nanoline structures on EOF has not yet been studied in detail and its understanding is lacking. Numerical analyses of the effect of nanoline orientation angle θ on EOF to reveal the associated mechanisms were conducted in this investigation. When θ increases from 5° to 90° (from parallel to perpendicular to the flow direction), the average EOF velocity decreases exponentially due to the increase in distortion of the applied electric field distribution at the structured surface, as a result of the increased apparent nanolines per unit microchannel length. With increasing nanoline width W, the decrease of average EOF velocity is fairly linear, attributed to the simultaneous narrowing of nanoline ridge (high local fluid velocity region). While increasing nanoline depth D results in a monotonic decrease of the average EOF velocity. This reduction stabilizes for aspect ratio D/W > 0.5 as the electric field distribution distortion within the nanoline trench remains nearly constant. This investigation reveals that the effects on EOF of nanolines, and by extrapolation for any nanostructures, may be directly attributed to their effects on the distortion of the applied electric field distribution within a microchannel.

Influence of the Electrophoretic Motion of Particle Suspensions on the Bulk Electroosmotic Flow of Water Through Fused Silica Capillaries

2005 ◽  
Author(s):  
J. Young ◽  
D. Maynes ◽  
B. W. Webb
Keyword(s):  
Chemical Composition ◽  
Electric Field ◽  
Applied Electric Field ◽  
Electroosmotic Flow ◽  
Charged Particles ◽  
Fused Silica ◽  
Particle Type ◽  
Fused Silica Capillaries ◽  
Silica Capillaries ◽  
Positively Charged

The influence of microparticles on electroosmotic flow was investigated experimentally. Experiments were conducted using four different particle types of varying chemical composition, surface charge and polarity. Each particle type was tested at five different volume fractions ranging from 0.001 – 0.025. With a constant applied electric field, positively charged particles enhanced the electroosmotic flow by as much as 800%. The enhancement depended on particle composition, size and concentration. For negatively charged particles, the bulk electroosmotic flow was retarded with the largest reductions being 35%.

LIQUID CRYSTLASLIGHT SCATTERING BY FLUCTUATIONS INDUCED BY AN APPLIED ELECTRIC FIELD IN A NEMATIC LIQUID CRYSTAL (APAPA)

1972 ◽  
Vol 33 (C1) ◽  
pp. C1-63-C1-67 ◽  
Author(s):  
M. BERTOLOTTI ◽  
B. DAINO ◽  
P. Di PORTO ◽  
F. SCUDIERI ◽  
D. SETTE
Keyword(s):  
Liquid Crystal ◽  
Electric Field ◽  
Nematic Liquid Crystal ◽  
Applied Electric Field

Improved technique for measuring mechanical deformations induced by an applied electric field to an organic insulator

2012 ◽  
Vol 15 (2-3) ◽  
pp. 127-139
Author(s):  
Tung Tran Anh ◽  
Laurent Berquez ◽  
Laurent Boudou ◽  
Juan Martinez-Vega ◽  
Alain Lacarnoy
Keyword(s):  
Electric Field ◽  
Applied Electric Field ◽  
Mechanical Deformations ◽  
Improved Technique

Solution for a Semi-Permeable Interface Crack in Elastic Dielectric/Piezoelectric Bimaterials

2008 ◽  
Vol 75 (1) ◽  
Author(s):  
Q. Li ◽  
Y. H. Chen
Keyword(s):  
Electric Field ◽  
Mechanical Loading ◽  
Interface Crack ◽  
Applied Electric Field ◽  
Crack Tip ◽  
Crack Model ◽  
Permeable Crack ◽  
Impermeable Crack ◽  
Silicon Oil ◽  
Elastic Dielectric

A semi-permeable interface crack in infinite elastic dielectric/piezoelectric bimaterials under combined electric and mechanical loading is studied by using the Stroh complex variable theory. Attention is focused on the influence induced from the permittivity of the medium inside the crack gap on the near-tip singularity and on the energy release rate (ERR). Thirty five kinds of such bimaterials are considered, which are constructed by five kinds of elastic dielectrics and seven kinds of piezoelectrics, respectively. Numerical results for the interface crack tip singularities are calculated. We demonstrate that, whatever the dielectric phase is much softer or much harder than the piezoelectric phase, the structure of the singular field near the semi-permeable interface crack tip in such bimaterials always consists of the singularity r−1∕2 and a pair of oscillatory singularities r−1∕2±iε. Calculated values of the oscillatory index ε for the 35 kinds of bimaterials are presented in tables, which are always within the range between 0.046 and 0.088. Energy analyses for five kinds of such bimaterials constructed by PZT-4 and the five kinds of elastic dielectrics are studied in more detail under four different cases: (i) the crack is electrically conducting, (ii) the crack gap is filled with air/vacuum, (iii) the crack gap is filled with silicon oil, and (iv) the crack is electrically impermeable. Detailed comparisons on the variable tendencies of the crack tip ERR against the applied electric field are given under some practical electromechanical loading levels. We conclude that the different values of the permittivity have no influence on the crack tip singularity but have significant influences on the crack tip ERR. We also conclude that the previous investigations under the impermeable crack model are incorrect since the results of the ERR for the impermeable crack show significant discrepancies from those for the semi-permeable crack, whereas the previous investigations under the conducting crack model may be accepted in a tolerant way since the results of the ERR show very small discrepancies from those for the semi-permeable crack, especially when the crack gap is filled with silicon oil. In all cases under consideration the curves of the ERR for silicon oil are more likely tending to those for the conducting crack rather than to those for air or vacuum. Finally, we conclude that the variable tendencies of the ERR against the applied electric field have an interesting load-dependent feature when the applied mechanical loading increases. This feature is due to the nonlinear relation between the normal electric displacement component and the applied electromechanical loadings from a quadratic equation.

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