Investigation of the Inertial Focusing Behavior in Curved Microfluidic Channels for Different Aspect Ratio

2016 ◽  
Author(s):  
Alireza Setayesh Hagh ◽  
Ali Dinler
Keyword(s):  
Particle Separation ◽  
Microfluidic Channels ◽  
Flow Conditions ◽  
Specific Flow ◽  
Inertial Focusing ◽  
Particle Focusing ◽  
Curved Channels ◽  
Aspect Ratios ◽  
Specific Number ◽  
Significant Attention

Inertial focusing has attracted a significant attention in microfluidics applications in recent years. Inertial focusing occurs only under specific flow conditions at which particles migrate across streamlines to a specific number of equilibrium positions. This behavior is mostly not sensitive to the particle size in straight channels. However, curved channels can allow sized based particle separation. In this study, curved channels with various aspect ratios have been investigated by numerical simulations. Consideration of flow regimes reveals that some conditions establish a high-quality single-particle focusing situation which is characterized by the alignment of particles within a narrow band. The outcomes of our numerical model contribute to the understanding of limitation of particle focusing and particle separation in curved microchannels.

scholarly journals Differential Sorting of Microparticles Using Spiral Microchannels with Elliptic Configurations

Micromachines ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 412
Author(s):  
Kaan Erdem ◽  
Vahid Ebrahimpour Ahmadi ◽  
Ali Kosar ◽  
Lütfullah Kuddusi
Keyword(s):  
Cell Sorting ◽  
Microfluidic Channel ◽  
Major Axis ◽  
Label Free ◽  
Flow Rates ◽  
Inertial Focusing ◽  
Size Dependent ◽  
Curved Channels ◽  
Aspect Ratios ◽  
Dependent Cell

Label-free, size-dependent cell-sorting applications based on inertial focusing phenomena have attracted much interest during the last decade. The separation capability heavily depends on the precision of microparticle focusing. In this study, five-loop spiral microchannels with a height of 90 µm and a width of 500 µm are introduced. Unlike their original spiral counterparts, these channels have elliptic configurations of varying initial aspect ratios, namely major axis to minor axis ratios of 3:2, 11:9, 9:11, and 2:3. Accordingly, the curvature of these configurations increases in a curvilinear manner through the channel. The effects of the alternating curvature and channel Reynolds number on the focusing of fluorescent microparticles with sizes of 10 and 20 µm in the prepared suspensions were investigated. At volumetric flow rates between 0.5 and 3.5 mL/min (allowing separation), each channel was tested to collect samples at the designated outlets. Then, these samples were analyzed by counting the particles. These curved channels were capable of separating 20 and 10 µm particles with total yields up to approximately 95% and 90%, respectively. The results exhibited that the level of enrichment and the focusing behavior of the proposed configurations are promising compared to the existing microfluidic channel configurations.

scholarly journals Inertial focusing in a parallelogram profiled microchannel over a range of aspect ratios

2019 ◽  
Vol 7 (1) ◽  
Author(s):  
Joo Young Kwon ◽  
Dong-Ki Lee ◽  
Jungwoo Kim ◽  
Young Hak Cho
Keyword(s):  
Aspect Ratio ◽  
Cfd Simulation ◽  
Rectangular Cross Section ◽  
Wet Etching ◽  
Pdms Mold ◽  
Rectangular Microchannel ◽  
Inertial Focusing ◽  
Particle Focusing ◽  
Aspect Ratios ◽  
Si Wafer

AbstractIn this study, particle focusing phenomena are studied in parallelogram and rectangular cross-sectioned microchannels of varying aspect ratio. In contrast to prior work the microchannels were fabricated using anisotropic wet etching of a Si wafer, plasma bonding, and self-alignment between the Si channel and the PDMS mold. It is shown that the inertial focusing points of the fabricated microchannels of parallelogram and rectangular cross-section were modified as the aspect ratio of the microchannels changed. The particle focusing points of the parallelogram profiled microchannel are compared with those of the rectangular microchannel through experimental measurements and CFD simulation. It is shown that particles can be efficiently focused and separated at a relatively low Reynolds number using a parallelogram profiled microchannel with a low aspect ratio.

The Effect of Asymmetry on Particle Focusing in Microchannels

2011 ◽  
Vol 403-408 ◽  
pp. 482-485 ◽  
Author(s):  
Levent Trabzon ◽  
Huseyin Kizil ◽  
Levent Yobas ◽  
Arzu Ozbey ◽  
Mustafa Yilmaz ◽  
...  
Keyword(s):  
Quantitative Analysis ◽  
High Throughput ◽  
Channel Wall ◽  
The Other ◽  
Clear Relationship ◽  
Single Line ◽  
Microfluidic Channels ◽  
Throughput Performance ◽  
Particle Focusing ◽  
Curved Channels

We studied the effect of geometry on single focusing of particles in the passive microfluidic channels. There is a quantitative analysis of focusing on non-axisymmetric straight channels with two different unique designs as well as curved channels having symmetrical and asymmetrical radius of curvatures in one turn. We found that there is a clear relationship in existence of single line focusing with the degree of non-symmetry in microchannels. One-degree of asymmetry in straight channels does not induce any formation of single focusing, but single line focusing is pronounced by two-degree of asymmetry in straight channels. On the other hand, single line focusing in the curved channels is enhanced with asymmetrical radius of curvatures in one turn. The single line focusing in curved channels is seen at Rep values higher than 1, which gives us better continuous and high-throughput performance. The position of single focused particles in the microchannels is found to be 50 m with respect to the channel wall in the asymmetrical curved microchannels.

scholarly journals Inertial Focusing and Separation of Particles in Similar Curved Channels

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Yue Ying ◽  
Ying Lin
Keyword(s):  
Reynolds Number ◽  
High Reynolds Number ◽  
Particle Separation ◽  
Separation Potential ◽  
Inertial Focusing ◽  
Focusing Effect ◽  
Serpentine Channel ◽  
Curved Channels ◽  
Wave Channel ◽  
High Reynolds

Abstract Inertial particle focusing in curved channels has enormous potential for lab-on-a-chip applications. This paper compares a zigzag channel, which has not been used previously for inertial focusing studies, with a serpentine channel and a square wave channel to explore their differences in terms of focusing performance and separation possibilities. The particle trajectories and fluid fields in the curved channels are studied by a numerical simulation. The effects of different conditions (structure, Reynolds number, and particle size) on the competition between forces and the focusing performance are studied. The results indicate that the zigzag channel has the best focusing effect at a high Reynolds number and that the serpentine channel is second in terms of performance. Regarding the particle separation potential, the zigzag channel has a good performance in separating 5 μm and 10 μm particles at ReC = 62.5. In addition, the pressure drop of the channel is also considered to evaluate the channel performance, which has not been taken into account in the literature on inertial microfluidics. This result is expected to be instructive for the selection and optimization of inertial microchannel structures.

scholarly journals A density-based threshold model for evaluating the separation of particles in heterogeneous mixtures with curvilinear microfluidic channels

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Chun Kwan Chen ◽  
Bee Luan Khoo
Keyword(s):  
Particle Density ◽  
Threshold Model ◽  
Particle Separation ◽  
Microfluidic Channels ◽  
Label Free ◽  
Inertial Focusing ◽  
Irregular Shapes ◽  
Mathematical Expressions ◽  
Nonlinear Channels ◽  
Sorting Efficiency

Abstract Particle separation techniques play an important role in biomedical research. Inertial focusing based microfluidics using nonlinear channels is one of the promising label-free technologies for biological applications. The particle separation is achieved as a result of the combination of inertial lift force (FL) and Dean drag force (FD). Although the mathematical expressions of FL and FD have been well derived in prior studies, they are still complicated, which limits their popularity in practice. Recent studies modified these expressions through experiments and proposed a threshold model, which assumes that only particles larger than the threshold will be well focused. Although this threshold model has been used in recent studies, two varying versions of the threshold model (TM1 and TM2) prevents standardisation in practice. In addition, both models were developed with regular low-density particles and may not be applicable to samples with higher density or samples with irregular shapes. Here, we evaluated the threshold models with samples of different densities. Based on these evaluations, we derived a modified model (TM4), which additionally considers the factor of particle density to improve the accuracy of existing models. Our results demonstrated that TM4 could more reliably predict the sorting efficiency of samples within a wider density range.

scholarly journals High-resolution particle separation by inertial focusing in high aspect ratio curved microfluidics

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Javier Cruz ◽  
Klas Hjort
Keyword(s):  
High Resolution ◽  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Biological Fluids ◽  
Essential Feature ◽  
Particle Separation ◽  
Size Difference ◽  
Inertial Focusing ◽  
Complex Samples ◽  
Wide Range

AbstractThe ability to focus, separate and concentrate specific targets in a fluid is essential for the analysis of complex samples such as biological fluids, where a myriad of different particles may be present. Inertial focusing is a very promising technology for such tasks, and specially a recently presented variant, inertial focusing in High Aspect Ratio Curved systems (HARC systems), where the systems are easily engineered and focus the targets together in a stable position over a wide range of particle sizes and flow rates. However, although convenient for laser interrogation and concentration, by focusing all particles together, HARC systems lose an essential feature of inertial focusing: the possibility of particle separation by size. Within this work, we report that HARC systems not only do have the capacity to separate particles but can do so with extremely high resolution, which we demonstrate for particles with a size difference down to 80 nm. In addition to the concept for particle separation, a model considering the main flow, the secondary flow and a simplified expression for the lift force in HARC microchannels was developed and proven accurate for the prediction of the performance of the systems. The concept was also demonstrated experimentally with three different sub-micron particles (0.79, 0.92 and 1.0 µm in diameter) in silicon-glass microchannels, where the resolution in the separation could be modulated by the radius of the channel. With the capacity to focus sub-micron particles and to separate them with high resolution, we believe that inertial focusing in HARC systems is a technology with the potential to facilitate the analysis of complex fluid samples containing bioparticles like bacteria, viruses or eukaryotic organelles.

Inertial focusing and zeta potential measurements of single-nanoparticles using octet-nanochannels

Lab on a Chip ◽  
2021 ◽  
Author(s):  
Shohei Kishimoto ◽  
Makusu Tsutsui ◽  
Kazumichi Yokota ◽  
Masateru Taniguchi
Keyword(s):  
Zeta Potential ◽  
Inertial Effects ◽  
Inertial Focusing ◽  
Particle Focusing ◽  
Single Nanoparticle

Electrokinetics in octet nanochannels was demonstrated to enable particle focusing via inertial effects to accurate single-nanoparticle zeta-potential measurements.

scholarly journals Self-Aligned Interdigitated Transducers for Acoustofluidics

2016 ◽  
Author(s):  
Zhichao Ma ◽  
Adrian J. T. Teo ◽  
Say Hwa Tan ◽  
Ye Ai ◽  
Nam-Trung Nguyen
Keyword(s):  
Acoustic Wave ◽  
Surface Acoustic Wave ◽  
Particle Separation ◽  
Microfluidic Devices ◽  
Current Approach ◽  
Droplet Generation ◽  
Microfluidic Channels ◽  
Clean Room ◽  
Precise Location ◽  
Innovative Method

Surface acoustic wave (SAW) is effective for the manipulation of fluids and particles in microscale. The current approach of integrating interdigitated transducers (IDTs) for SAW generation into microfluidic channels involves complex and laborious microfabrication steps. These steps often require the full access to clean room facilities and hours to align the transducers to the precise location. This work presents an affordable and innovative method for fabricating SAW-based microfluidic devices without the need of clean room facilities and alignment. The IDTs and microfluidic channels are fabricated in the same process and thus precisely self-aligned in accordance with the device design. With the use of the developed fabrication approach, a few types of different SAW-based microfluidic devices have been fabricated and demonstrated for particle separation and active droplet generation.

scholarly journals Polyacrylamide Ferrogels with Ni Nanowires

Materials ◽  
2019 ◽  
Vol 12 (16) ◽  
pp. 2582 ◽  
Author(s):  
Alexander P. Safronov ◽  
Bethanie J. H. Stadler ◽  
Joseph Um ◽  
Mohammad Reza Zamani Kouhpanji ◽  
Javier Alonso Masa ◽  
...  
Keyword(s):  
Anodic Aluminum Oxide ◽  
Hysteresis Loops ◽  
Magnetic Response ◽  
Magnetic Nanowires ◽  
Anodic Aluminum ◽  
Aspect Ratios ◽  
Anodic Aluminum Oxide Templates ◽  
Basic Studies ◽  
Significant Attention ◽  
Magnetization Reversal Process

Nickel magnetic nanowires (NWs) have attracted significant attention due to their unique properties, which are useful for basic studies and technological applications, for example in biomedicine. Their structure and magnetic properties were systematically studied in the recent years. In this work, Ni NWs with high aspect ratios (length/diameter ~250) were fabricated by electrodeposition into commercial anodic aluminum oxide templates. The templates were then etched and the NWs were suspended in water, where their hydrodynamic size was evaluated by dynamic light scattering. The magnetic response of these NWs as a function of an external magnetic field indicates a dominant shape anisotropy with propagation of the vortex domain wall as the main magnetization reversal process. The suspension of Ni NWs was used in the synthesis of two types of polyacrylamide ferrogels (FGs) by free radical polymerization, with weight fractions of Ni NWs in FGs of 0.036% and 0.169%. The FGs were reasonably homogeneous. The magnetic response of these FGs (hysteresis loops) indicated that the NWs are randomly oriented inside the FG, and their magnetic response remains stable after embedding.

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