scholarly journals Theory and computational study of electrophoretic ion separation and focusing in microfluidic channels

2012 ◽  
Vol 17 (4) ◽  
pp. 431-447 ◽  
Author(s):  
Oleksiy V. Klymenko ◽  
Christian Amatore ◽  
Wen Sun ◽  
Yong-Liang Zhou ◽  
Zhao-Wu Tian ◽  
...  
Keyword(s):  
Computational Study ◽  
Electrical Contact ◽  
Channel Length ◽  
Microfluidic Channels ◽  
Solution Flow ◽  
Ion Separation ◽  
Microfluidic Separation ◽  
2D Simulation ◽  
Ion Focusing ◽  
Ion Conducting

In this work we describe the theory and 2D simulation of ion separation and focusing in a new concept of microfluidic separation device. The principle of the method of ion focusing is classical in the sense that it consists in opposing a hydrodynamic transport ensured by the solution flow to an electrophoretic driving force so that any ionic sample results poised within the microchannel at the point where the two forces equilibrate. The originality of the concept investigated here relies on the fact that thanks to the use of an ion-conducting membrane of variable thickness in electrical contact with the channel the electrophoretic force is varied continuously all along the channel length. Similarly, changing the geometric shape of the membrane allows a facile optimization of the device separation and focusing properties.

scholarly journals Characterization of Mixing Performance Induced by Double Curved Passive Mixing Structures in Microfluidic Channels

Micromachines ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 556
Author(s):  
Ingrid. H. Oevreeide ◽  
Andreas Zoellner ◽  
Bjørn. T. Stokke
Keyword(s):  
Flow Direction ◽  
Stationary Flow ◽  
Channel Length ◽  
Small Sample ◽  
Confocal Imaging ◽  
Microfluidic Channels ◽  
High Performing ◽  
Passive Micromixer ◽  
Passive Mixing ◽  
Parameter Values

Functionalized sensor surfaces combined with microfluidic channels are becoming increasingly important in realizing efficient biosensing devices applicable to small sample volumes. Relaxing the limitations imposed by laminar flow of the microfluidic channels by passive mixing structures to enhance analyte mass transfer to the sensing area will further improve the performance of these devices. In this paper, we characterize the flow performance in a group of microfluidic flow channels with novel double curved passive mixing structures (DCMS) fabricated in the ceiling. The experimental strategy includes confocal imaging to monitor the stationary flow patterns downstream from the inlet where a fluorophore is included in one of the inlets in a Y-channel microfluidic device. Analyses of the fluorescence pattern projected both along the channel and transverse to the flow direction monitored details in the developing homogenization. The mixing index (MI) as a function of the channel length was found to be well accounted for by a double-exponential equilibration process, where the different parameters of the DCMS were found to affect the extent and length of the initial mixing component. The range of MI for a 1 cm channel length for the DCMS was 0.75–0.98, which is a range of MI comparable to micromixers with herringbone structures. Overall, this indicates that the DCMS is a high performing passive micromixer, but the sensitivity to geometric parameter values calls for the selection of certain values for the most efficient mixing.

Ion creation, ion focusing, ion/molecule reactions, ion separation, and ion detection in the open air in a small plastic device

The Analyst ◽  
2015 ◽  
Vol 140 (3) ◽  
pp. 696-700 ◽  
Author(s):  
Zane Baird ◽  
Pu Wei ◽  
R. Graham Cooks
Keyword(s):  
Ambient Conditions ◽  
Ion Detection ◽  
Ion Separation ◽  
Small Plastic ◽  
Ion Molecule Reactions ◽  
Ion Focusing ◽  
Electrode Assemblies ◽  
3D Printed

Ion manipulation in air is demonstrated with 3D printed plastic electrode assemblies. The ability to focus, react, separate, and detect ions under ambient conditions is shown.

Epitaxial ferroelectric thin films

1994 ◽  
Vol 52 ◽  
pp. 572-573
Author(s):  
S. G. Ghonge ◽  
E. Goo ◽  
R. Ramesh ◽  
R. Haakenaasen ◽  
D. K. Fork
Keyword(s):  
Single Crystal ◽  
Work Function ◽  
Nonvolatile Memory ◽  
Ferroelectric Properties ◽  
Electrical Contact ◽  
Memory Devices ◽  
Ferroelectric Films ◽  
Si Substrates ◽  
Electro Optic ◽  
Wide Range

Microstructure of epitaxial ferroelectric/conductive oxide heterostructures on LaAIO3(LAO) and Si substrates have been studied by conventional and high resolution transmission electron microscopy. The epitaxial films have a wide range of potential applications in areas such as non-volatile memory devices, electro-optic devices and pyroelectric detectors. For applications such as electro-optic devices the films must be single crystal and for applications such as nonvolatile memory devices and pyroelectric devices single crystal films will enhance the performance of the devices. The ferroelectric films studied are Pb(Zr0.2Ti0.8)O3(PLZT), PbTiO3(PT), BiTiO3(BT) and Pb0.9La0.1(Zr0.2Ti0.8)0.975O3(PLZT).Electrical contact to ferroelectric films is commonly made with metals such as Pt. Metals generally have a large difference in work function compared to the work function of the ferroelectric oxides. This results in a Schottky barrier at the interface and the interfacial space charge is believed to responsible for domain pinning and degradation in the ferroelectric properties resulting in phenomenon such as fatigue.

A Method of Fabricating Electroplated Structures using Side-wall Electrical Contact

2014 ◽  
Vol 134 (2) ◽  
pp. 20-25 ◽  
Author(s):  
Takanori Aono ◽  
Yasuhiro Yoshimura ◽  
Yoshinori Nakayama ◽  
Masatoshi Kanamaru
Keyword(s):  
Electrical Contact ◽  
Side Wall

On the Properties of an Ion Conductive System Incorporated in Hybrid Films

2000 ◽  
Vol 628 ◽  
Author(s):  
G. González ◽  
P. J. Retuert ◽  
S. Fuentes
Keyword(s):  
Electrochemical Impedance ◽  
Ternary Phase Diagram ◽  
Lithium Perchlorate ◽  
Molar Ratio ◽  
Ionic Conductors ◽  
X Ray Diffraction ◽  
Poly Ethylene Oxide ◽  
Ion Conducting ◽  
Poly Ethylene ◽  
High Degree

ABSTRACTBlending the biopolymer chitosan (CHI) with poly (aminopropilsiloxane) oligomers (pAPS), and poly (ethylene oxide) (PEO) in the presence of lithium perchlorate lead to ion conducting products whose conductivity depends on the composition of the mixture. A ternary phase diagram for mixtures containing 0.2 M LiClO4 shows a zone in which the physical properties of the products - transparent, flexible, mechanically robust films - indicate a high degree of molecular compatibilization of the components. Comparison of these films with binary CHI-pAPS nanocomposites as well as the microscopic aspect, thermal behavior, and X-ray diffraction pattern of the product with the composition PEO/CHI/pAPS/LiClO4 1:0.5:0.6:0.2 molar ratio indicates that these films may be described as a layered nanocomposite. In this composite, lithium species coordinated by PEO and pAPS should be inserted into chitosan layers. Electrochemical impedance spectroscopy measurements indicate the films are pure ionic conductors with a maximal bulk conductivity of 1.7*10-5 Scm-1 at 40 °C and a sample-electrode interface capacitance of about 1.2*10-9 F.

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