Barrier contactless dielectrophoresis: A new approach to particle separation

2019 ◽  
Vol 2 (2) ◽  
pp. 59-68 ◽  
Author(s):  
Sergey N. Podoynitsyn ◽  
Olga N. Sorokina ◽  
Maksim A. Klimov ◽  
Igor I. Levin ◽  
Sergey B. Simakin
Keyword(s):  
Particle Separation ◽  
New Approach

Acoustic focusing with engineered node locations for high-performance microfluidic particle separation

The Analyst ◽  
2014 ◽  
Vol 139 (5) ◽  
pp. 1192-1200 ◽  
Author(s):  
Erika J. Fong ◽  
Amanda C. Johnston ◽  
Timothy Notton ◽  
Seung-Yong Jung ◽  
Klint A. Rose ◽  
...  
Keyword(s):  
High Throughput ◽  
High Performance ◽  
High Efficiency ◽  
Particle Separation ◽  
Main Channel ◽  
Thin Wall ◽  
Device Design ◽  
Secondary Channel ◽  
New Approach ◽  
Acoustic Focusing

We present a new approach to acoustofluidic device design with a secondary channel separated from the main channel by a thin wall. This allows off-center placement of acoustic nodes, which enables high-efficiency and high-throughput separation of cell-scale objects.

A New Approach to the Prediction of Particle Separation by Sieving in Flour Milling

2001 ◽  
Vol 79 (4) ◽  
pp. 211-218 ◽  
Author(s):  
F.M. Sultanbawa ◽  
W.G. Owens ◽  
S.S. Pandiella
Keyword(s):  
Particle Separation ◽  
New Approach ◽  
Flour Milling

scholarly journals Gradient acoustic focusing of sub-micron particles for separation of bacteria from blood lysate

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
David Van Assche ◽  
Elisabeth Reithuber ◽  
Wei Qiu ◽  
Thomas Laurell ◽  
Birgitta Henriques-Normark ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Biomedical Applications ◽  
Acoustic Streaming ◽  
Particle Separation ◽  
Submicron Particles ◽  
New Approach ◽  
Volume Force ◽  
Acoustic Focusing ◽  
Flow Through

AbstractHandling of submicron-sized objects is important in many biochemical and biomedical applications, but few methods today can precisely manipulate this range of particles. We present gradient acoustic focusing that enables flow-through particle separation of submicron particles and cells and we apply it for separation of bacteria from blood lysate to facilitate their detection in whole blood for improved diagnostics. To control suspended objects below the classical 2µm size limit for acoustic focusing, we introduce a co-flowing acoustic impedance gradient to generate a stabilizing acoustic volume force that supresses acoustic streaming. The method is validated theoretically and experimentally using polystyrene particles, Staphylococcus aureus, Streptococcus pneumoniae and Escherichia coli. The applicability of the method is demonstrated by the separation of bacteria from selectively chemically lysed blood. Combined with downstream operations, this new approach opens up for novel methods for sepsis diagnostics.

Modular Microfluidic Filters Based on Transparent Membranes

2016 ◽  
Vol 138 (4) ◽  
Author(s):  
E. Archibong ◽  
H. Tuazon ◽  
H. Wang ◽  
J. Winskas ◽  
A. L. Pyayt
Keyword(s):  
Microfluidic Chip ◽  
Membrane Damage ◽  
Particle Separation ◽  
Live Cells ◽  
New Approach ◽  
Silicon Nitride Membrane ◽  
Particle Imaging ◽  
Silicon Based ◽  
Functional Components ◽  
Low Pressures

We propose a new approach to the modular packaging of microfluidic components, in which different functional components are not only fabricated separately but are also designed to be individually removable for the purposes of replacement or subsequent analysis. In this paper, we demonstrate one such component: a stand-alone microfluidic filter that can be custom-fabricated and then connected, disconnected, and replaced on a microfluidic chip as needed. This filter is also designed such that particles captured on the filter can be further analyzed or processed directly on the filter itself—for example, for microscopic examination or cell culturing. The filter is a thin (1 μm) transparent silicon nitride membrane that can be designed and fabricated according to specifications for different applications. This material is suitable for microscale fabrication; filtration of a variety of solutions, including biological samples; and subsequent particle imaging and processing. The porous nature of the thin filter allows for particle separation under relatively low pressures, thus protecting the particles from rupture or membrane damage. We describe two methods for integrating the filter apparatus onto a microfluidic chip such that it can be inserted, removed, and replaced. To demonstrate the utility of this approach, we fabricated custom-designed silicon-based filters, incorporated them onto microfluidic systems then filtered microparticles and live cells from test solutions, and finally removed the filters to image the microparticles and culture the cells directly on the filter membranes.

scholarly journals Continuous Particle Separation Driven by 3D Ag-PDMS Electrodes with Dielectric Electrophoretic Force Coupled with Inertia Force

Micromachines ◽  
2022 ◽  
Vol 13 (1) ◽  
pp. 117
Author(s):  
Xiaohong Li ◽  
Junping Duan ◽  
Zeng Qu ◽  
Jiayun Wang ◽  
Miaomiao Ji ◽  
...  
Keyword(s):  
Electric Field ◽  
Particle Separation ◽  
Silica Particles ◽  
Uniform Electric Field ◽  
Inertia Force ◽  
New Approach ◽  
Field Distributions ◽  
Novel Approach ◽  
3D Electrodes ◽  
Biological And Medical Applications

Cell separation has become @important in biological and medical applications. Dielectrophoresis (DEP) is widely used due to the advantages it offers, such as the lack of a requirement for biological markers and the fact that it involves no damage to cells or particles. This study aimed to report a novel approach combining 3D sidewall electrodes and contraction/expansion (CEA) structures to separate three kinds of particles with different sizes or dielectric properties continuously. The separation was achieved through the interaction between electrophoretic forces and inertia forces. The CEA channel was capable of sorting particles with different sizes due to inertial forces, and also enhanced the nonuniformity of the electric field. The 3D electrodes generated a non-uniform electric field at the same height as the channels, which increased the action range of the DEP force. Finite element simulations using the commercial software, COMSOL Multiphysics 5.4, were performed to determine the flow field distributions, electric field distributions, and particle trajectories. The separation experiments were assessed by separating 4 µm polystyrene (PS) particles from 20 µm PS particles at different flow rates by experiencing positive and negative DEP. Subsequently, the sorting performances of the 4 µm PS particles, 20 µm PS particles, and 4 µm silica particles with different solution conductivities were observed. Both the numerical simulations and the practical particle separation displayed high separating efficiency (separation of 4 µm PS particles, 94.2%; separation of 20 µm PS particles, 92.1%; separation of 4 µm Silica particles, 95.3%). The proposed approach is expected to open a new approach to cell sorting and separating.

The O–C diagrams of minor planets − a new approach to modelling the rotation

1999 ◽  
Vol 173 ◽  
pp. 185-188
Author(s):  
Gy. Szabó ◽  
K. Sárneczky ◽  
L.L. Kiss
Keyword(s):  
Error Analysis ◽  
Time Dependence ◽  
Theoretical Work ◽  
Minor Planet ◽  
Minor Planets ◽  
New Approach ◽  
Preliminary Results ◽  
Ccd Observations

AbstractA widely used tool in studying quasi-monoperiodic processes is the O–C diagram. This paper deals with the application of this diagram in minor planet studies. The main difference between our approach and the classical O–C diagram is that we transform the epoch (=time) dependence into the geocentric longitude domain. We outline a rotation modelling using this modified O–C and illustrate the abilities with detailed error analysis. The primary assumption, that the monotonity and the shape of this diagram is (almost) independent of the geometry of the asteroids is discussed and tested. The monotonity enables an unambiguous distinction between the prograde and retrograde rotation, thus the four-fold (or in some cases the two-fold) ambiguities can be avoided. This turned out to be the main advantage of the O–C examination. As an extension to the theoretical work, we present some preliminary results on 1727 Mette based on new CCD observations.

A New Approach to the Demonstration of Oxidase-Localization Using Tannic Acid Or Catechin

1973 ◽  
Vol 31 ◽  
pp. 698-699
Author(s):  
V. Mizuhira ◽  
Y. Futaesaku
Keyword(s):  
Cross Section ◽  
Tannic Acid ◽  
Elastic Fiber ◽  
The Other ◽  
New Approach ◽  
Tissue Block ◽  
Active Reaction ◽  
The Cross

Previously we reported that tannic acid is a very effective fixative for proteins including polypeptides. Especially, in the cross section of microtubules, thirteen submits in A-tubule and eleven in B-tubule could be observed very clearly. An elastic fiber could be demonstrated very clearly, as an electron opaque, homogeneous fiber. However, tannic acid did not penetrate into the deep portion of the tissue-block. So we tried Catechin. This shows almost the same chemical natures as that of proteins, as tannic acid. Moreover, we thought that catechin should have two active-reaction sites, one is phenol,and the other is catechole. Catechole site should react with osmium, to make Os- black. Phenol-site should react with peroxidase existing perhydroxide.

Processing Immunoperoxidase Labeled Cell Monolayers and Cryostat Sesctions For Electron Microscopy

1985 ◽  
Vol 43 ◽  
pp. 714-715
Author(s):  
K. Chien ◽  
R. Van de Velde ◽  
I.P. Shintaku ◽  
A.F. Sassoon
Keyword(s):  
Cell Monolayer ◽  
Cell Types ◽  
Surface Antigens ◽  
Immunoperoxidase Method ◽  
Reaction Step ◽  
Hot Plate ◽  
Air Drying ◽  
New Approach ◽  
Cell Monolayers ◽  
Glass Slides

Immunoelectron microscopy of neoplastic lymphoma cells is valuable for precise localization of surface antigens and identification of cell types. We have developed a new approach in which the immunohistochemical staining can be evaluated prior to embedding for EM and desired area subsequently selected for ultrathin sectioning.A freshly prepared lymphoma cell suspension is spun onto polylysine hydrobromide- coated glass slides by cytocentrifugation and immediately fixed without air drying in polylysine paraformaldehyde (PLP) fixative. After rinsing in PBS, slides are stained by a 3-step immunoperoxidase method. Cell monolayer is then fixed in buffered 3% glutaraldehyde prior to DAB reaction. After the DAB reaction step, wet monolayers can be examined under LM for presence of brown reaction product and selected monolayers then processed by routine methods for EM and embedded with the Chien Re-embedding Mold. After the polymerization, the epoxy blocks are easily separated from the glass slides by heatingon a 100°C hot plate for 20 seconds.

TEM study of a biofilm on copper corrosion

1996 ◽  
Vol 54 ◽  
pp. 220-221
Author(s):  
W. A. Chiou ◽  
N. Kohyama ◽  
B. Little ◽  
P. Wagner ◽  
M. Meshii
Keyword(s):  
Marine Bacterium ◽  
Culture Medium ◽  
Copper Alloys ◽  
Pure Copper ◽  
Localized Corrosion ◽  
Natural Seawater ◽  
Copper Corrosion ◽  
New Approach ◽  
The Past ◽  
Copper Tolerant

The corrosion of copper and copper alloys in a marine environment is of great concern because of their widespread use in heat exchangers and steam condensers in which natural seawater is the coolant. It has become increasingly evident that microorganisms play an important role in the corrosion of a number of metals and alloys under a variety of environments. For the past 15 years the use of SEM has proven to be useful in studying biofilms and spatial relationships between bacteria and localized corrosion of metals. Little information, however, has been obtained using TEM capitalizing on its higher spacial resolution and the transmission observation of interfaces. The research presented herein is the first step of this new approach in studying the corrosion with biological influence in pure copper.Commercially produced copper (Cu, 99%) foils of approximately 120 μm thick exposed to a copper-tolerant marine bacterium, Oceanospirillum, and an abiotic culture medium were subsampled (1 cm × 1 cm) for this study along with unexposed control samples.

High resolution at low voltage: A new approach

1989 ◽  
Vol 47 ◽  
pp. 76-77
Author(s):  
Arthur V. Jones
Keyword(s):  
Low Voltage ◽  
Emission Sources ◽  
New Approach ◽  
Design Concepts ◽  
Probe Diameter ◽  
Low Voltage Operation ◽  
Sufficient Intensity ◽  
Electron Microscopes ◽  
Scanning Electron Microscopes ◽  
Immersion Type

With the introduction of field-emission sources and “immersion-type” objective lenses, the resolution obtainable with modern scanning electron microscopes is approaching that obtainable in STEM and TEM-but only with specific types of specimens. Bulk specimens still suffer from the restrictions imposed by internal scattering and the need to be conducting. Advances in coating techniques have largely overcome these problems but for a sizeable body of specimens, the restrictions imposed by coating are unacceptable.For such specimens, low voltage operation, with its low beam penetration and freedom from charging artifacts, is the method of choice.Unfortunately the technical dificulties in producing an electron beam sufficiently small and of sufficient intensity are considerably greater at low beam energies — so much so that a radical reevaluation of convential design concepts is needed.The probe diameter is usually given by

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