Study of Angle-of-Attack (AoA) for Airfoil in Deterministic Lateral Displacement (DLD)

2019 ◽  
Author(s):  
Kawkab Ahasan ◽  
Jong-Hoon Kim
Keyword(s):  
High Throughput ◽  
Lateral Displacement ◽  
Angle Of Attack ◽  
Critical Diameter ◽  
Control Flow ◽  
Flow Rates ◽  
Deterministic Lateral Displacement ◽  
Potential Applications ◽  
High Reynolds ◽  
Flow Symmetry

Abstract Deterministic lateral displacement (DLD) is a method of inertial size-based particle separation with potential applications in high throughput sample processing, such as the fractionation of blood or the purification of target species like viral particles or circulating tumor cells. Recently, it has been shown that symmetric airfoils with neutral angle-of-attack (AoA) can be used for high-throughput design of DLD device, due to their mitigation of vortex effects and preservation of flow symmetry under high Reynolds number (Re) conditions. While high-Re operation with symmetric airfoils has been established, the effect of AoA for airfoil on the DLD performance has not been characterized. In this study, we present a high-Re investigation with symmetric airfoil-shaped pillars having positive and negative 15 degree AoA. Both positive and negative AoA configurations yield significant flow anisotropy at higher flow rates. The stronger shift of the critical diameter (Dc) was observed with negative AoA, but not in positive AoA device. The most likely contributor may be the growing anisotropy that develops in the AoA device at higher flow rates. This study shows that high-Re DLD design with airfoil shaped pillars requires significant consideration for pillar orientation to control flow symmetry.

Characterizing the High Reynolds Number Regime for Deterministic Lateral Displacement (DLD) Devices

2017 ◽  
Author(s):  
Brian Dincau ◽  
Arian Aghilinejad ◽  
Jong-Hoon Kim ◽  
Xiaolin Chen
Keyword(s):  
Reynolds Number ◽  
Laminar Flow ◽  
Soft Lithography ◽  
Lateral Displacement ◽  
Flow Characteristics ◽  
Critical Diameter ◽  
Flow Rates ◽  
Deterministic Lateral Displacement ◽  
Array Configuration ◽  
High Reynolds

Deterministic lateral displacement (DLD) is a common name given to a class of continuous microfluidic separation devices that use a repeating array of pillars to selectively displace particles having a mean diameter greater than the critical diameter (Dc). This Dc is an emergent property influenced by pillar shape, size, and spacing, in addition to the suspending fluid and target particle properties. The majority of previous research in DLD applications has focused on the utilization of laminar flow in low Reynolds number (Re) regimes. While laminar flow exhibits uniform streamlines and predictable separation characteristics, this low-Re regime is dependent on relatively low fluid velocities, and may not hold true at higher processing speeds. Through numerical modeling and experimentation, we investigated high-Re flow characteristics and potential separation enhancements resulting from vortex generation within a DLD array. We used an analytical model and computational software to simulate DLD performance spanning a Re range of 1–100 at flow rates of 2–170 μL/s (0.15–10 mL/min). Each simulated DLD array configuration was composed of 60 μm cylindrical pillars with a 45 μm gap size. The experimental DLD device was fabricated using conventional soft lithography, and injected with 20 μm particles at varying flow rates to observe particle trajectories. The simulated results predict a shift in Dc at Re > 50, while the experimental results indicate a breakdown of typical DLD operation at Re > 70.

Limits of Parabolic Flow Theory in Microfluidic Particle Separation: A Computational Study

2013 ◽  
Author(s):  
Ryan S. Pawell ◽  
Tracie J. Barber ◽  
David W. Inglis ◽  
Robert A. Taylor
Keyword(s):  
Computational Study ◽  
Lateral Displacement ◽  
Particle Separation ◽  
Flow Profile ◽  
Flow Rates ◽  
Deterministic Lateral Displacement ◽  
Flow Development ◽  
Separation Threshold ◽  
Parabolic Flow ◽  
Size Based Separation

Microfluidic particle separation technologies are useful for enriching rare cell populations for academic and clinical purposes. In order to separate particles based on size, deterministic lateral displacement (DLD) arrays are designed assuming that the flow profile between posts is parabolic or shifted parabolic (depending on post geometry). The design process also assumes the shape of the normalized flow profile is speed-invariant. The work presented here shows flow profile shapes vary, in arrays with circular and triangular posts, from this assumption at practical flow rates (10 < Re < 100). The root-mean-square error (RMSE) of this assumption in the circular post arrays peaked at 0.144. The RMSE in the triangular post array peaked at 0.136. Flow development occurred more rapidly in circular post arrays when compared to triangular post arrays. Additionally, the changes in critical bumping diameter (DCB) the DLD design metric used to calculate the size-based separation threshold were examined for 10 different row shift fractions (FRS). These errors correspond to a DCB that varies as much as 11.7% in the circular post arrays and 15.1% in the triangular post arrays.

Vortex-free high-Reynolds deterministic lateral displacement (DLD) via airfoil pillars

2018 ◽  
Vol 22 (12) ◽  
Author(s):  
Brian M. Dincau ◽  
Arian Aghilinejad ◽  
Xiaolin Chen ◽  
Se Youn Moon ◽  
Jong-Hoon Kim
Keyword(s):  
Lateral Displacement ◽  
Deterministic Lateral Displacement ◽  
High Reynolds

Towards Deep Learning Approaches for Quantitative Analysis of High-Throughput DLD

2020 ◽  
Author(s):  
Eric A. Gioe ◽  
Xiaolin Chen ◽  
Jong-Hoon Kim
Keyword(s):  
Deep Learning ◽  
High Throughput ◽  
Lateral Displacement ◽  
Great Promise ◽  
Learning Approaches ◽  
Timely Manner ◽  
Particle Detection ◽  
New Techniques ◽  
Deterministic Lateral Displacement ◽  
Total Particle

Abstract Microfluidics has shown great promise for the sorting or separation of biological cells such as circulating tumor cells since the first studies came out a few decades ago. With recent advances in high-throughput microfluidics, analysis of massive amounts of data needs to be completed in an iterative, timely manner. However, the majority of analysis is either performed manually or through the use of superimposing multiple images to define the flow of the particles, taking a significant amount of time to complete. The objective of the work is to increase the efficiency and repeatability of particle detection in a high-throughput deterministic lateral displacement (DLD) device. The program proposed is in the early stages of development, but shows promise. The average time it takes to analyze over a gigabyte of video is 24.21 seconds. The average percent error of the total particle detection was 21.42%. The assumptions made for the initial version of the program affect the accuracy of the particle in wall detection, so new techniques that do not follow the assumptions will need to be investigated. More work will be completed to implement machine learning or deep learning to assist in the development of DLD devices.

scholarly journals Broken flow symmetry explains the dynamics of small particles in deterministic lateral displacement arrays

2017 ◽  
pp. 201706645 ◽  
Author(s):  
Sung-Cheol Kim ◽  
Benjamin H. Wunsch ◽  
Huan Hu ◽  
Joshua T. Smith ◽  
Robert H. Austin ◽  
...  
Keyword(s):  
Lateral Displacement ◽  
Small Particles ◽  
Deterministic Lateral Displacement ◽  
Flow Symmetry

Effects of the particle deformability on the critical separation diameter in the deterministic lateral displacement device

2014 ◽  
Vol 743 ◽  
pp. 60-74 ◽  
Author(s):  
Shangjun Ye ◽  
Xueming Shao ◽  
Zhaosheng Yu ◽  
Wenguang Yu
Keyword(s):  
Lateral Displacement ◽  
Critical Diameter ◽  
Longitudinal Direction ◽  
Simulation Method ◽  
Lateral Position ◽  
Particle Deformation ◽  
Deterministic Lateral Displacement ◽  
Critical Separation ◽  
Elastic Particle ◽  
Separation Diameter

AbstractDeterministic lateral displacement (DLD) technology is a newly developed method which can separate microscale and nanoscale particles continuously and efficiently. In this paper, a direct numerical simulation method (i.e. a fictitious domain method) is used to simulate the motion of an elastic particle (modelled as homogeneously elastic body) in the DLD device. The effects of the particle deformability on the critical separation diameter are investigated. Our results indicate that there exists a critical deformability, below which the critical diameter decreases with increasing deformability, whereas beyond which the critical diameter increases with increasing deformability. The reasons are discussed via the consideration of the effects of the particle deformation and the lubrication force on the lateral position of the particle centre point. In addition, our results show that the increase in the gap distance between adjacent posts in both directions or in the longitudinal direction alone leads to the increase in the critical particle size with respect to the gap size, which can be explained by the lateral position of the separation streamline of the undisturbed flow.

scholarly journals AC electrokinetic biased deterministic lateral displacement for tunable particle separation

Lab on a Chip ◽  
2019 ◽  
Vol 19 (8) ◽  
pp. 1386-1396 ◽  
Author(s):  
Victor Calero ◽  
Pablo Garcia-Sanchez ◽  
Carlos Honrado ◽  
Antonio Ramos ◽  
Hywel Morgan
Keyword(s):  
Lateral Displacement ◽  
Critical Diameter ◽  
Particle Separation ◽  
Separation Technique ◽  
Deterministic Lateral Displacement

We describe a novel particle separation technique that combines deterministic lateral displacement (DLD) with orthogonal electrokinetic forces to separate particles below the critical diameter.

Sign in / Sign up

Export Citation Format

Share Document