scholarly journals Transport Analysis of RF Drift-velocity Filter Employing Crossed DC and AC Electric Fields for Ion Swarm Experiments

1995 ◽  
Vol 48 (3) ◽  
pp. 491 ◽  
Author(s):  
K Iinuma ◽  
M Takebe
Keyword(s):  
Electric Fields ◽  
Drift Velocity ◽  
Analytical Formula ◽  
Transmission Efficiency ◽  
Ion Separation ◽  
Velocity Filter ◽  
Ac Electric Fields ◽  
Operational Characteristics ◽  
Cs Ions ◽  
And Diffusion

The operational characteristics of the RF drift-velocity filter developed recently by us to separate a mixture of gaseous ions are examined theoretically. The solutions of the appropriate transport equations provide an analytical formula for the transmission efficiency of the filter in terms of the mobility and diffusion coefficient of the ions, the electric field strength, the RF frequency and the filter dimension. Using the experimental transport data for Li+ /Xe and Cs+ /Xe, the formula was tested and we find that it adequately accounts for the degree of ion separation achieved by the filter at high gas pressures. The variation of the profiles of the arrival time spectra for Li+, Na+ and Cs+ ions in C02, obtained by our drift-tube experiments, also supports this analysis.

scholarly journals Anomalous Anisotropic Diffusion of Electron Swarms in AC Electric Fields

1995 ◽  
Vol 48 (6) ◽  
pp. 925 ◽  
Author(s):  
RD White ◽  
RE Robson ◽  
KF Ness
Keyword(s):  
Electric Fields ◽  
Diffusion Coefficients ◽  
Anisotropic Diffusion ◽  
Time Varying ◽  
Longitudinal Diffusion ◽  
Temporal Behaviour ◽  
Ac Electric Fields ◽  
Wide Range ◽  
First Time ◽  
And Diffusion

A time-dependent multi-term solution of the Boltzmann equation is used to calculate the drift and diffusion coefficients of electron swarms in gases under the influence of a time varying electric field. Two model gases are considered and for a.c. electric fields results are presented for a wide range of applied frequencies. Of particular interest is the anomalous temporal behaviour of the longitudinal diffusion coefficient, which is discussed here for the first time.

Manipulation of Bio-Particles in Microelectrode Structures by Means of Non-Uniform AC Electric Fields

2002 ◽  
Author(s):  
Antonio Castellanos ◽  
Antonio Ramos ◽  
Antonio Gonza´lez ◽  
Hywel Morgan ◽  
Nicolas Green
Keyword(s):  
Electric Fields ◽  
Mass Density ◽  
Fluid Motion ◽  
Electrode System ◽  
Viscous Drag ◽  
Diffuse Double Layer ◽  
Ac Electroosmosis ◽  
Ac Electric Fields ◽  
High Electric Fields ◽  
And Diffusion

Non-uniform ac electric fields induce movement of polarizable particles. This phenomenon, known as dielectrophoresis, is useful to manipulate bioparticles. High electric fields when used in bio-separation systems give rise to fluid motion, which in turn results in a viscous drag on the particle. These fields generate heat, leading to volume forces in the liquid. Gradients in conductivity and permittivity rise to electrothermal forces; gradients in mass density to buoyancy. Also non-uniform ac electric fields produce forces on the induced charges in the diffuse double layer on the electrodes, and the resulting steady fluid motion has been termed ac electroosmosis. The effects of Brownian motion and diffusion are also discussed in this context. The orders of magnitude of the various forces experienced by a submicrometre particle in a model electrode system are calculated. The results are compared with experiments and the relative influence of each type of force is described.

Fabrication of ZrO 2 /rGO nanocomposites by flash sintering under AC electric fields

2021 ◽  
Author(s):  
Xinghua Su ◽  
Mengying Fu ◽  
Gai An ◽  
Zhihua Jiao ◽  
Qiang Tian ◽  
...  
Keyword(s):  
Electric Fields ◽  
Ac Electric Fields ◽  
Flash Sintering

AC Electrokinetics for Biosensors

2004 ◽  
Author(s):  
M. Sigurdson ◽  
C. Meinhart ◽  
D. Wang
Keyword(s):  
Electric Fields ◽  
Dna Hybridization ◽  
Fluid Motion ◽  
Diffusive Transport ◽  
Analyte Concentration ◽  
Ac Electrokinetics ◽  
Ac Electric Fields ◽  
Binding Rate ◽  
Electrothermal Flow ◽  
Biosensor Device

We develop here tools for speeding up binding in a biosensor device through augmenting diffusive transport, applicable to immunoassays as well as DNA hybridization, and to a variety of formats, from microfluidic to microarray. AC electric fields generate the fluid motion through the well documented but unexploited phenomenon, Electrothermal Flow, where the circulating flow redirects or stirs the fluid, providing more binding opportunities between suspended and wall-immobilized molecules. Numerical simulations predict a factor of up to 8 increase in binding rate for an immunoassay under reasonable conditions. Preliminary experiments show qualitatively higher binding after 15 minutes. In certain applications, dielectrophoretic capture of passing molecules, when combined with electrothermal flow, can increase local analyte concentration and further enhance binding.

scholarly journals Spinning Janus doublets driven in uniform ac electric fields

2014 ◽  
Vol 89 (1) ◽  
Author(s):  
Alicia Boymelgreen ◽  
Gilad Yossifon ◽  
Sinwook Park ◽  
Touvia Miloh
Keyword(s):  
Electric Fields ◽  
Ac Electric Fields
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