Dielectrophoresis induced clustering regimes of viable yeast cells

Kadaksham, J.; Singh, Pushpendra; Aubry, Nadine

doi:10.1002/elps.200500133

Cited by 47 publications

(30 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Similarly, the electrostatic interactions among polarized particles, which normally cause the particles to cluster in the direction of the electric field when particles are suspended in a bulk fluid (mutual attraction leading to chain formation), create here repulsive forces instead, thus preventing the particles from clustering. To further explain this, we note that when the line joining the centers of two particles is perpendicular to the electric field, the force acting on them is repulsive and when it is parallel the force is attractive (16)(17)(18)(19)(20)(21)(22)(23). The former orientation, however, is typically unstable, and therefore, particles of an electrorheological suspension cluster into chains aligned with the electric field direction.…”

Section: Resultsmentioning

confidence: 99%

“…However, the repulsive forces caused by the interparticles electrostatic interactions (Eq. 2) decay relatively faster (5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23) with the distance between the particles (these forces decay as r Ϫ4 ). Because the repulsive force decays faster than the attractive capillary force, there is an equilibrium distance at which the two curves intersect and the total lateral force acting on the particles is zero.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Micro- and nanoparticles self-assembly for virtually defect-free, adjustable monolayers

Aubry

Singh

Janjua

et al. 2008

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

As chips further shrink toward smaller scales, fabrication processes based on the self-assembly of individual particles into patterns or structures are often sought. One of the most popular techniques for two-dimensional assembly (self-assembled monolayers) is based on capillary forces acting on particles placed at a liquid interface. Capillarity-induced clustering, however, has several limitations: it applies to relatively large (radius > Ϸ10 m) particles only, the clustering is usually non-defect-free and lacks long-range order, and the lattice spacing cannot be adjusted. The goal of the present article is to show that these shortcomings can be addressed by using an external electric field normal to the interface. The resulting self-assembly is capable of controlling the lattice spacing statically or dynamically, forming virtually defect-free monolayers, and manipulating a broad range of particle sizes and types including nanoparticles and electrically neutral particles.nterparticle force-driven self-assembly processes are often used to form materials with desired micro-and nanostructures (1, 2). In these processes, the forces, such as intermolecular or capillary forces, bring the particles together and cause them to arrange locally according to a pattern that depends on the orientational nature of these forces (1-5). Many envisioned applications of nanotechnology and fabrication of mesoscopic objects strongly rely on the manufacturing of such micro-and nanostructured materials (6-8). Future progress in this area will critically depend on our ability to accurately control the particle arrangement (e.g., lattice spacing, defect-free capability, and long-range order) in three dimensions (3D) and in two dimensions (2D) for a broad range of particle sizes, shapes, and types. Such a control in 2D will lead to the manufacture of controlled monolayers or ultrafine porous membranes with adjustable, but regular, pore sizes, and therefore with adaptable mechanical, thermal, electrical, and/or optical properties (e.g., controlled nanofluidic drug delivery patches with adjustable mass transfer properties across the patch, nanofilters for protein separation based on their sizes, electronic nanocircuits with improved performance in absence of defects, photonic devices, etc.).A popular mean used to assemble particles is based on the phenomenon of capillarity (3-5, 9-15). A common example of capillarity-driven self-assembly is the clustering of cereal flakes floating on the surface of milk. The floating cereal particles experience attractive capillary forces, because when two such particles are close to each other, the deformed interface around them is not symmetric because the interface height between the particles is lowered owing to the interfacial tension (9-15). This lowering of the interface between the particles gives rise to lateral forces that cause them to come together. Capillarityinduced clustering has several deficiencies: (i) the resulting particle structure is usually not defect-free: defects take place because...

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Micro- and nanoparticles self-assembly for virtually defect-free, adjustable monolayers

Aubry

Singh

Janjua

et al. 2008

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

show abstract

“…Notice that the value of Clausius-Mossotti factor is between −0.5 and 1.0. In a non-uniform electric field, the particle-particle interaction force on the i th particle due to the j th particle is obtained by accounting for the spatial variation of the electric field [33][34][35][36] …”

Section: Point-dipole and Maxwell Stress Tensor Approachesmentioning

confidence: 99%

Direct Numerical Simulation of Particles in Spatially Varying Electric Fields †

Amah

Janjua

Singh

2018

Fluids

Self Cite

View full text Add to dashboard Cite

Abstract:A numerical scheme is developed to simulate the motion of dielectric particles in the uniform and nonuniform electric fields of microfluidic devices. The motion of particles is simulated using a distributed Lagrange multiplier method (DLM) and the electric force acting on the particles is calculated by integrating the Maxwell stress tensor (MST) over the particle surfaces. One of the key features of the DLM method used is that the fluid-particle system is treated implicitly by using a combined weak formulation, where the forces and moments between the particles and fluid cancel, as they are internal to the combined system. The MST is obtained from the electric potential, which, in turn, is obtained by solving the electrostatic problem. In our numerical scheme, the domain is discretized using a finite element scheme and the Marchuk-Yanenko operator-splitting technique is used to decouple the difficulties associated with the incompressibility constraint, the nonlinear convection term, the rigid-body motion constraint and the electric force term. The numerical code is used to study the motion of particles in a dielectrophoretic cage which can be used to trap and hold particles at its center. If the particles moves away from the center of the cage, a resorting force acts on them towards the center. The MST results show that the ratio of the particle-particle interaction and dielectrophoretic forces decreases with increasing particle size. Therefore, larger particles move primarily under the action of the dielectrophoretic (DEP) force, especially in the high electric field gradient regions. Consequently, when the spacing between the electrodes is comparable to the particle size, instead of collecting on the same electrode by forming chains, they collect at different electrodes.

show abstract

“…Similar interactions take place between particles in a nonuniform electric field [27,30,31]. Direct numerical simulations (DNS) conducted using this expression for the interaction force show that two particles subjected to a nonuniform electric field attract each other and orient such that the line joining their centers is parallel to the local electric field direction while they move together toward the location where the electric field strength is locally maximal or minimal, depending on the value of their dielectric constant relative to that of the two fluids [32][33][34]. The extent of this attraction, which, if it is strong, manifests itself in particle chaining, depends on a dimensionless parameter which can also be found in the above references.…”

Section: Dep Forces On Particlesmentioning

confidence: 99%

Concentrating particles on drop surfaces using external electric fields

et al. 2008

Self Cite

View full text Add to dashboard Cite

We propose to use an externally applied uniform electric field to alter the distribution of particles on the surface of a drop immersed in another immiscible liquid. Specifically, we seek to generate well-defined concentrated regions at the drop surface while leaving the rest of the surface particle free. Experiments show that when the dielectric constant of the drop is greater than that of the ambient liquid the particles for which the Clausius-Mossotti factor is positive move along the drop surface to the two poles of the drop. Particles with a negative Clausius-Mossotti factor, on the other hand, move along the drop surface to form a ring near the drop equator. The opposite takes place when the dielectric constant of the drop is smaller than that of the ambient liquid, namely particles for which the Clausius-Mossotti factor is positive form a ring near the equator while those for which such a factor is negative move to the poles. This motion is due to the dielectrophoretic force that acts upon particles because the electric field on the surface of the drop is nonuniform, despite the uniformity of the applied electric field. Experiments also show that when small particles collect at the poles of a deformed drop the electric field needed to break the drop is smaller than without particles. These phenomena could be useful to concentrate particles at a drop surface within well-defined regions (poles and equator), separate two types of particles at the surface of a drop or increase the drop deformation to accelerate drop breakup.

show abstract

Dielectrophoresis induced clustering regimes of viable yeast cells

Cited by 47 publications

References 17 publications

Micro- and nanoparticles self-assembly for virtually defect-free, adjustable monolayers

Micro- and nanoparticles self-assembly for virtually defect-free, adjustable monolayers

Direct Numerical Simulation of Particles in Spatially Varying Electric Fields †

Concentrating particles on drop surfaces using external electric fields

Contact Info

Product

Resources

About