Multidomain Oriented Particle Chains Based on Spatial Electric Field and Their Optical Application

Suspension system is a type of structural equipment attached to the wheels of a vehicle for the purpose of reducing the effects of irregularities on road surfaces. This paper investigates the Magneto rheological (MR) suspension system in motorcycle and compares its advantages with the passive suspension system. Passive suspension element can only store and dissipate energy associated with local relative motion. Moreover its energy cannot be controlled as the suspension properties remain fixed at all time, unlike MR suspension which has the ability to overcome these drawbacks. The characteristic of the latter is related to micron-sized particles, typically iron, that forms particle chains, when appropriate electric field is applied. Two modelling approaches which are the Bouc-Wen model and Sim models, were used in this research. By comparing these two MR models and passive suspension system, it can be concluded that the Bouc-Wen model gives the best result. It is also shown that MR suspension systems reduce the displacement amplitude around 30% whereas the time settling is reduced from 10 to 3 seconds, compared to the passive suspension system.

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INTERACTION BETWEEN PARTICLES AND PARTICLE CHAINS IN ELECTRORHEOLOGICAL FLUIDS

International Journal of Modern Physics B ◽

10.1142/s0217979201005568 ◽

2001 ◽

Vol 15 (06n07) ◽

pp. 1033-1041 ◽

Cited By ~ 4

Author(s):

GUO-QING GU ◽

P. M. HUI

Keyword(s):

Electric Field ◽

Standard Form ◽

Approximate Expression ◽

Electrostatic Energy ◽

Granular System ◽

Analytic Expressions ◽

Rigorous Framework ◽

A Chain ◽

Er Fluids ◽

Particle Chains

The electric potential in a granular system consisting of spherical inclusions in the presence of an external applied electric field is studied in detail within the framework of the Rayleigh identity. The effects of induced charges on the inclusions are taken into account explicitly. The method, in principle, includes the effects of all multipoles. The method is applied to study the interaction between two inclusions. The standard form of interaction between inclusions widely used in studying ER fluids is recovered as an approximation of our general approach. We then apply the method to a chain of inclusions. Analytic expressions for the electrostatic energy per inclusion and the electric field are obtained for the case in which the chain is parallel to the applied field. Our result reduces to the form used in the literature when appropriate approximation is taken. The method is further extended to study the interaction between chains of inclusions. An approximate expression is obtained for the force between two chains of inclusions. Our approach provides a rigorous framework for determining the interaction between inclusions and chains of inclusions to arbitrary accuracy.

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Particle Separation Using Dielectrophoresis

Fluids Engineering ◽

10.1115/imece2003-43950 ◽

2003 ◽

Cited By ~ 1

Author(s):

J. Kadaksham ◽

P. Singh ◽

N. Aubry

Keyword(s):

Dielectric Properties ◽

Electric Field ◽

Lagrange Multiplier ◽

Numerical Scheme ◽

Particle Separation ◽

Dielectrophoretic Force ◽

Dipole Interactions ◽

Time Required ◽

Particle Chains ◽

Er Fluid

A numerical scheme based on the distributed Lagrange multiplier (DLM) method is used to simulate the process of separation of particles with different dielectric properties suspended in an electrorheological (ER) fluid and subjected to a nonuniform electric field. The dielectrophoresis induced separation of particles is possible only when the sign of Clausius-Mossoti factor for the particles is different, as in this case the dielectrophoretic force moves them to different regions of the device. The time required for separation of particle in simulations is larger than that given by an order or magnitude analysis because of the formation of particle chains which arise due to the dipole-dipole interactions among the particles and move much more slowly than isolated particles.

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Resolution in photoelectron microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100086593 ◽

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.

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Field-assisted ionization theory for microscopists

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100171833 ◽

1994 ◽

Vol 52 ◽

pp. 820-821

Author(s):

Patrick P. Camus

Keyword(s):

Electric Field ◽

Electron Tunneling ◽

Ionization Probability ◽

Critical Distance ◽

Tunneling Probability ◽

Field Ionization ◽

Radius Of Curvature ◽

Field Evaporation ◽

A Value ◽

Ion Emission

The theory of field ion emission is the study of electron tunneling probability enhanced by the application of a high electric field. At subnanometer distances and kilovolt potentials, the probability of tunneling of electrons increases markedly. Field ionization of gas atoms produce atomic resolution images of the surface of the specimen, while field evaporation of surface atoms sections the specimen. Details of emission theory may be found in monographs.Field ionization (FI) is the phenomena whereby an electric field assists in the ionization of gas atoms via tunneling. The tunneling probability is a maximum at a critical distance above the surface,xc, Fig. 1. Energy is required to ionize the gas atom at xc, I, but at a value reduced by the appliedelectric field, xcFe, while energy is recovered by placing the electron in the specimen, φ. The highest ionization probability occurs for those regions on the specimen that have the highest local electric field. Those atoms which protrude from the average surfacehave the smallest radius of curvature, the highest field and therefore produce the highest ionizationprobability and brightest spots on the imaging screen, Fig. 2. This technique is called field ion microscopy (FIM).

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