Vesicle dynamics in uniform electric fields: squaring and breathing

Soft Matter ◽  
2015 ◽  
Vol 11 (24) ◽  
pp. 4840-4846 ◽  
Author(s):  
Lane C. McConnell ◽  
Petia M. Vlahovska ◽  
Michael J. Miksis
Keyword(s):  
Electric Fields ◽  
Ac Electric Fields ◽  
Vesicle Dynamics ◽  
Ac Field ◽  
Prolate Ellipsoidal ◽  
Dynamic Transitions

We computationally investigate the dynamics of a vesicle exposed to uniform DC or AC electric fields. Our simulations capture the “squaring” phenomenon, in which vesicles deform into rectangular profiles with corner-like regions of high curvature, as vesicles undergo dynamic transitions between oblate and prolate ellipsoidal shapes. In AC field, this occurs periodically resembling “breathing”.

scholarly journals Долговечность полимеров в переменном электрическом поле

2020 ◽  
Vol 90 (2) ◽  
pp. 251
Author(s):  
В.А. Закревский ◽  
В.А. Пахотин ◽  
Н.Т. Сударь
Keyword(s):  
Free Radicals ◽  
Excited States ◽  
Electric Fields ◽  
Charge Accumulation ◽  
Nonradiative Relaxation ◽  
Polymer Dielectric ◽  
Ac Electric Fields ◽  
Ac Field ◽  
The Difference ◽  
Electron Excited States

An explanation of the difference in the electrical properties of polymers in the DC and AC electric fields is proposed. Energy release during recombination of electrons and holes injected into a polymer dielectric is considered as a factor accelerating the processes of electric aging of these dielectrics in an AC field. It is shown that nonradiative relaxation of electron excited states causes breaks of bonds in macromolecules and formation of free radicals. Due to the lower ionization energy of free radicals (compared to the original molecules), the rate of charge accumulation in the polymer dielectric increases, which leads to a decrease in its durability in an AC field compared to the durability of polymers in a DC field.

Dielectric properties of BaTiO3–BaZrO3 ceramics under a high electric field

2002 ◽  
Vol 17 (4) ◽  
pp. 755-759 ◽  
Author(s):  
T. Tsurumi ◽  
Y. Yamamoto ◽  
H. Kakemoto ◽  
S. Wada ◽  
H. Chazono ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Dielectric Permittivity ◽  
Field Dependence ◽  
Electric Fields ◽  
Broad Maximum ◽  
Ac Electric Fields ◽  
Ceramic Disk ◽  
Ac Field ◽  
Ac Fields ◽  
Temperature Side

Multilayered ceramic capacitors (MLCCs) with BaTiO3–BaZrO3 (BTZ) dielectric layers were fabricated, and the dielectric permittivity of the BTZ layers with different thicknesses in MLCCs was measured. The dielectric permittivity of the BTZ ceramic disk was also measured under various ac electric fields. The variation in the dielectric behaviors with the thickness of BTZ layers in MLCCs was explained by the ac-field dependence of dielectric permittivity observed in the BTZ ceramic disk. The ac-field dependence of dielectric permittivity of BTZ was markedly observed below the temperature of a broad maximum in the dielectric permittivity versus temperature (є versus T) curve. It was found that the temperature of the broad maximum shifted to the low-temperature side and the peak shape became asymmetric with increasing ac field. These changes in the dielectric properties under high ac fields were explained by a model of relaxors with the concept of the formation of polar microregions (PMRs) and the freezing of fluctuating ipoles in PMRs.

Gentle Dielectrophoretic Focusing of Yeast Cells in Curved Microchannels

2009 ◽  
Author(s):  
Christopher Church ◽  
Gaoyan Wang ◽  
Junjie Zhu ◽  
Tzuen-Rong Jeremy Tzeng ◽  
Xiangchun Xuan
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Cell Concentration ◽  
Yeast Cells ◽  
Field Frequency ◽  
Electric Field Magnitude ◽  
Ac Electric Fields ◽  
Microfluidic Flow ◽  
Dc Electric Field ◽  
Ac Field

Focusing cells into a tight stream is usually a necessary step prior to counting, detecting and sorting them in, for example, microfluidic flow cytometers. We present herein a simple and gentle cell focusing technique in physiological solutions through a serpentine microchannel using DC-biased AC electric fields. This electrokinetic focusing eliminates sheath flows and in-channel microelectrodes. It results from the cross-stream dielectrophoretic motion of cells induced by the intrinsic channel curvatures. The effects of electric field magnitude, AC to DC electric field ratio, AC field frequency, and cell concentration on the focusing performance of yeast cells will be studied.

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

Anomalous Particle Rotation and Resulting Microstructure of Colloids in AC Electric Fields

Langmuir ◽  
2008 ◽  
Vol 24 (22) ◽  
pp. 12842-12848 ◽  
Author(s):  
Pushkar P. Lele ◽  
Manish Mittal ◽  
Eric M. Furst
Keyword(s):  
Electric Fields ◽  
Particle Rotation ◽  
Ac Electric Fields ◽  
Anomalous Particle
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