Spatiotemporally resolved measurements of electric field around a piezoelectric transformer using electric-field induced second harmonic (E-FISH) generation

2021 ◽  
Author(s):  
Jinyu Yang ◽  
Ed V Barnat ◽  
Seong-kyun Im ◽  
David B. Go
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Second Harmonic ◽  
Surrounding Medium ◽  
Input Voltage ◽  
Piezoelectric Transformer ◽  
Power Sources ◽  
Plasma Generation ◽  
Distal Surface ◽  
The Face

Abstract When a piezoelectric transformer (PT) is actuated at its second harmonic frequency by a low input voltage, the generated electric field at the distal end can be sufficient to breakdown the surrounding gas, making them attractive power sources for non-equilibrium plasma generation. Understanding the potential and electric fields produced in the surrounding medium by the PT is important for effectively designing and using PT plasma devices. In this work, the spatiotemporally resolved characteristics of the electric field generated by a PT operating in open air have been investigated using the femtosecond electric field-induced second harmonic generation (E-FISH) method. Electric field components were determined by simultaneously conducting E-FISH measurements with the incident laser polarized in two orthogonal directions relative to the PT crystal. Results of this work demonstrate the spatial distribution of electric field around the PT’s output distal end and how it evolves as a function of time. Notably, the strongest electric field appears on the face of the PT’s distal surface, near the top and bottom edges and decreases by approximately 70% over 3 mm. The time delay between the PT’s input voltage and measured electric field indicates that there is an about 0.45 phase difference between the PT’s input voltage and output signal.

PRELIMINARY OPTICAL STUDY ON ER FLUIDS

1994 ◽  
Vol 08 (20n21) ◽  
pp. 2921-2933 ◽  
Author(s):  
L. W. ZHOU ◽  
J. F. YE ◽  
R. B. TAO ◽  
Y. TANG ◽  
J. F. PENG ◽  
...  
Keyword(s):  
Phase Transition ◽  
Electric Field ◽  
Electric Fields ◽  
Nonlinear Optical ◽  
Second Harmonic ◽  
Optical Response ◽  
Optical Study ◽  
Solid States ◽  
Linear And Nonlinear ◽  
Er Fluids

Linear and nonlinear optical study on electrorheological (ER) fluids is reported. The ER fluids under the investigation were glass beads, zeolite and ferroelectrics. The linear optical response of some ER fluids showed sharp changes near critical electric fields. An enhancement of electric field induced second harmonic generations (EFISH) was observed as the function of E2, where E is the external electric field. The said enhancement is considered to be corresponding to a modulation of the material's refractive index associated with the electric field induced polarization of the delocalized electrons. The enhanced nonlinear optical response on the transition between liquid and solid states can be related to the phase transition in ER fluids.

scholarly journals Gas sensors based on dielectrophoresis of graphene, and graphene oxide, and reduced graphene oxide A Review

2020 ◽  
Author(s):  
shamim Azimi
Keyword(s):  
Graphene Oxide ◽  
Electric Field ◽  
Reduced Graphene Oxide ◽  
Electric Fields ◽  
Surrounding Medium ◽  
Diagnostic Technique ◽  
Environmental Research ◽  
Label Free ◽  
Reduced Graphene ◽  
Electrode Edge

Dielectrophoresis (DEP) is a label-free, accurate, fast, and low-cost diagnostic technique that uses the principles of polarization and the motion of bioparticles in applied electric fields. DEP occurs when uncharged particles in the solution are subject to a spatially non-uniform alternating-current (AC) electric field, resulting in the motion of particles by creating a polarizability gradient between the particles and the suspending medium. The movement of particles in DEP is based on the difference in polarizability between the particles and the surrounding medium. If the particles move toward the electrode edge, the region of high electric field gradient, the response is called positive DEP (p-DEP). At the same time, if the particles move away from the electrode edge, the response is called negative DEP (n-DEP). This phenomenon provides a powerful and versatile tool for the non-destructive manipulation of nanoscale materials, allowing for the control of the resistance and the type of the assembly. This technique has been proven to be beneficial in various fields, including environmental research, polymer research, sensors, biosensors, microfluidics, medicine, and diagnostics. This paper reviews the fundamentals of DEP and its specific application in the incorporation of graphene, graphene oxide(GO), and reduced graphene oxide(RGO), enabling the assembly of individual two-dimensional nanostructures at predefined locations in microdevices for gas sensor applications. The review provides an essential framework for parallel fabrication approaches of graphene-based devices.

Electric currents in the ionosphere - Ionization drift due to winds and electric fields

1953 ◽  
Vol 246 (913) ◽  
pp. 306-320 ◽  
Keyword(s):  
Electric Field ◽  
Electric Current ◽  
Electric Fields ◽  
Body Force ◽  
Surrounding Medium ◽  
The Other ◽  
Electric Currents ◽  
Vertical Drift ◽  
Meteor Trails ◽  
Current Flows

An analysis is made of the drift velocity of the (neutral) ionization in a uniform ionosphere under the influences of an electric field and/or atmospheric wind. It is shown that this drift of ionization produces the Ampere body force on the medium; the electric current flows perpendicular to the drift. The motion of a cylinder of ionization, of density differing from the surrounding medium, is then studied. It is found that the motion is electrodynamically stable, but unstable hydrodynamically, if Hall conductivity is appreciable. In the latter event there is rapid accretion of (neutral) ionization on one side of the cylinder, depletion on the other. It is suggested that this is the origin of sporadic E ( E 5 )ionization, and is likely to be an important factor in the production of the long-enduring meteor trails detected by radio methods. Formulae are derived for the horizontal and vertical drift of ionization at all latitudes in a thin ionosphere in which vertical electric currents are prohibited by polarization. Graphs are given which permit derivation of the true wind or field in a given region of the ionosphere from experimental observations of the drift velocities.

scholarly journals Electric Field Distribution Analysis of Blood Cancer as a Potential Blood Cancer Therapy

2021 ◽  
Vol 22 (2) ◽  
pp. 127
Author(s):  
Miftakhul Firdhaus ◽  
Ulya Farahdina ◽  
Vinda Zakiyatuz Zulfa ◽  
Endarko Endarko ◽  
Agus Rubiyanto ◽  
...  
Keyword(s):  
Cancer Therapy ◽  
Electric Field ◽  
Field Distribution ◽  
Electric Fields ◽  
B Lymphocyte ◽  
Electric Field Distribution ◽  
Input Voltage ◽  
Electrochemical Process ◽  
Distribution Analysis ◽  
Blood Cancer

Blood cancer causes a significant increase in the concentration of Leukocytes, which can be broken down through dielectrophoresis and electrochemical procedures. Therefore, the electric field plays an important role in the migration of leukocytes to high voltage areas. This is because different electrode arrangements produce varying electric field distributions. Furthermore, this study applied finite element methods to generate electric fields when electrodes with an AC voltage were applied to blood placed in a chamber. Therefore, in this study, variations of mediums and electrode arrangements were investigated, which led to the recommendation of 3 models. The objective was to investigate electrode arrangements that produce optimal electric field distribution for the three models to exhibit a booster of electric field distribution. The maximum electric field is generated close to the electrode (Z=2 mm and Z=92 mm) for any material (i.e. normal blood, B lymphocyte, and T lymphocyte) with values of 22.6 V/m and 23.47 V/m, 22.85 V/m and 22.97 V/m, and 24.88 V/m and 25.01 V/m. Based on principle, lymphocytes in the blood result in positive dielectrophoresis, since they migrate to a higher electric field close to the electrode, with enough input voltage to turn the electrochemical process on the leukocytes into electric current. Furthermore, this study provides new perspectives and ideas, which have not been revealed in previous studies on blood cancer therapy using the electric field of Ag electrode in blood cancer distribution.Keywords: blood cancer, dielectrophoresis, electric field, voltage, electrochemical, and cancer therapy.

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