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.

Numerical Simulation of Fluid Flow in Deterministic Lateral Displacement Devices

2013 ◽  
Author(s):  
Haidong Feng ◽  
Sanja Miskovic
Keyword(s):  
Fluid Flow ◽  
Tilt Angle ◽  
Separation Efficiency ◽  
Lateral Displacement ◽  
Flow Characteristics ◽  
Critical Diameter ◽  
Particle Separation ◽  
Deterministic Lateral Displacement ◽  
Pillar Diameter ◽  
Wide Range

Deterministic lateral displacement (DLD) is a continuous, flow-based micro-particle separation method. DLD takes advantage of the laminar nature of the fluid flow in microchannels by directing the small particles along the main streamline of the fluid flow, while laterally displacing larger particles along the axis of the micropillar array. When optimally designed, this simple and energy-efficient method allows a high-resolution separation of particle mixtures carried along by the liquid at high velocity. In this paper, a numerical modeling of fluid flow inside of different DLD devices at different Re numbers is performed. A parametric study is conducted to assess the variation of theoretical critical particle size for various DLD devices. Parameters that affect flow velocity distribution, such as shift fraction and tilt angle are studied. Simulation results show that both micropillar shift fraction and the tilt angle significantly affect the velocity profile within the DLD device. A model is presented to describe the critical diameter for a wide range of pillar-diameter-to-gap-size ratios. The possibility of achieving greater throughput, while preserving flow characteristics and therefore particle separation efficiency, is demonstrated.

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.

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.

scholarly journals Electrokinetically driven deterministic lateral displacement for particle separation in microfluidic devices

2014 ◽  
Vol 18 (5-6) ◽  
pp. 1195-1200 ◽  
Author(s):  
Srinivas Hanasoge ◽  
Raghavendra Devendra ◽  
Francisco J. Diez ◽  
German Drazer
Keyword(s):  
Lateral Displacement ◽  
Particle Separation ◽  
Microfluidic Devices ◽  
Deterministic Lateral Displacement

scholarly journals Efficient paradigm to enhance particle separation in deterministic lateral displacement arrays

2019 ◽  
Vol 1 (10) ◽  
Author(s):  
Amirali Ebadi ◽  
Mohammad Javad Farshchi Heydari ◽  
Reihaneh Toutouni ◽  
Bahareh Chaichypour ◽  
Morteza Fathipour ◽  
...  
Keyword(s):  
Lateral Displacement ◽  
Particle Separation ◽  
Deterministic Lateral Displacement
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