Spatially-Varying Electric Field Design by Planer Electrodes

2010 ◽  
pp. 77-116
Author(s):  
Mihoko Otake
Keyword(s):  
Electric Field ◽  
Spatially Varying

Ion motion in a spatially varying electric field

1993 ◽  
Author(s):  
P.L. Rothwell ◽  
M.B. Silevitch ◽  
L.P. Block ◽  
C.-G. Falthammar
Keyword(s):  
Electric Field ◽  
Ion Motion ◽  
Spatially Varying

Particle dynamics in a spatially varying electric field

1995 ◽  
Vol 100 (A8) ◽  
pp. 14875 ◽  
Author(s):  
Paul L. Rothwell ◽  
Michael B. Silevitch ◽  
Lars P. Block ◽  
Carl-Gunne Fälthammar
Keyword(s):  
Electric Field ◽  
Particle Dynamics ◽  
Spatially Varying

Effect of Frequency and Electrode Configuration on Yeast Cells Subjected to Traveling Electric Fields

2006 ◽  
Author(s):  
Sai Chaitanya Nudurupati ◽  
Pushpendra Singh ◽  
Nadine Aubry
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Equations Of Motion ◽  
Yeast Cells ◽  
Microfluidic Channels ◽  
Mems Devices ◽  
Carbonaceous Particles ◽  
Microfluidic Chamber ◽  
Spatially Varying ◽  
Traveling Wave Dielectrophoresis

There is great interest in trapping and manipulating small sized particles such as biological, glass, polymer and carbonaceous particles suspended in a liquid. One way to trap such micro/nano sized particles is by means of a microfluidic chamber equipped with electrodes at the bottom and thus generating conventional dielectrophoresis based on an electric field of spatially varying magnitude. In this work, we explore the use of traveling wave dielectrophoresis induced by an electric field of spatially varying phase, which offers both particle capturing/separation and transport capabilities (without having to pump the fluid itself). Particles are subjected to electrostatic and hydrodynamic forces and torques that are computed solving the full equations of motion for both the fluid and the particles without any modeling (from first principles) and using a finite element scheme based on the Distributed Lagrange Multiplier (DLM) method. We consider two typical microfluidic channels (MEMS devices) with electrodes embedded in the bottom wall. It is found that the motion and destination of the particles strongly depend on the frequency dependent complex Clausius-Mossotti factor (the mismatch between the particles and fluid electric properties), and that the hydrodynamic and electrostatic particle-particle interactions play a crucial role on the particles dynamics. These conclusions are demonstrated on model particles having the properties of yeast cells.

scholarly journals Multiscale response of ionic systems to a spatially varying electric field

2017 ◽  
Vol 2 (3) ◽  
Author(s):  
Jesper Schmidt Hansen
Keyword(s):  
Electric Field ◽  
Response Function ◽  
Mass Flux ◽  
Concentration Gradient ◽  
Potential Gradient ◽  
Planck Equation ◽  
Einstein Relation ◽  
Response Functions ◽  
Ionic Systems ◽  
Spatially Varying

In this paper the response of ionic systems subjected to a spatially varying electric field is studied. Following the Nernst-Planck equation, two forces driving the mass flux are present, namely, the concentration gradient and the electric potential gradient. The mass flux due to the concentration gradient is modelled through Fick’s law, and a new constitutive relation for the mass flux due to the potential gradient is proposed. In the regime of low screening the response function due to the potential gradient is closely related to the ionic conductivity. In the large screening regime, on the other hand, the response function is governed by the charge-charge structure. Molecular dynamics simulations are conducted and the two wavevector dependent response functions are evaluated for models of a molten salt and an ionic liquid. In the low screening regime the response functions show same wavevector dependency, indicating that it is the same underlying physical processes that govern the response. In the screening regime the wavevector dependency is very different and, thus, the overall response is determined by different processes. This is in agreement with the observed failure of the Nernst-Einstein relation.

Resolution in photoelectron microscopy

1991 ◽  
Vol 49 ◽  
pp. 458-459
Author(s):  
G. F. Rempfer
Keyword(s):  
Electron Microscopy ◽  
Electric Field ◽  
Ultraviolet Light ◽  
Uniform Field ◽  
Virtual Image ◽  
Lens System ◽  
Photoemission Electron Microscopy ◽  
Planar Electrode ◽  
Electron Lens ◽  
Photoemission Electron

In photoelectron microscopy (PEM), also called photoemission electron microscopy (PEEM), the image is formed by electrons which have been liberated from the specimen by ultraviolet light. The electrons are accelerated by an electric field before being imaged by an electron lens system. The specimen is supported on a planar electrode (or the electrode itself may be the specimen), and the accelerating field is applied between the specimen, which serves as the cathode, and an anode. The accelerating field is essentially uniform except for microfields near the surface of the specimen and a diverging field near the anode aperture. The uniform field forms a virtual image of the specimen (virtual specimen) at unit lateral magnification, approximately twice as far from the anode as is the specimen. The diverging field at the anode aperture in turn forms a virtual image of the virtual specimen at magnification 2/3, at a distance from the anode of 4/3 the specimen distance. This demagnified virtual image is the object for the objective stage of the lens system.

Sign in / Sign up

Export Citation Format

Share Document