Separation of polydisperse particle mixtures by deterministic lateral displacement. The impact of particle diffusivity on separation efficiency

2012 ◽  
Vol 7 ◽  
pp. S356-S371 ◽  
Author(s):  
S. Cerbelli
Keyword(s):  
Separation Efficiency ◽  
Lateral Displacement ◽  
Deterministic Lateral Displacement ◽  
Polydisperse Particle ◽  
The Impact

scholarly journals Combining Electrostatic, Hindrance and Diffusive Effects for Predicting Particle Transport and Separation Efficiency in Deterministic Lateral Displacement Microfluidic Devices

Biosensors ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 126
Author(s):  
Valentina Biagioni ◽  
Giulia Balestrieri ◽  
Alessandra Adrover ◽  
Stefano Cerbelli
Keyword(s):  
Particle Transport ◽  
Separation Efficiency ◽  
Lateral Displacement ◽  
Operating Conditions ◽  
Separation Performance ◽  
Label Free ◽  
Deterministic Lateral Displacement ◽  
Promising Tool ◽  
Label Free Detection ◽  
Diffusive Effects

Microfluidic separators based on Deterministic Lateral Displacement (DLD) constitute a promising technique for the label-free detection and separation of mesoscopic objects of biological interest, ranging from cells to exosomes. Owing to the simultaneous presence of different forces contributing to particle motion, a feasible theoretical approach for interpreting and anticipating the performance of DLD devices is yet to be developed. By combining the results of a recent study on electrostatic effects in DLD devices with an advection–diffusion model previously developed by our group, we here propose a fully predictive approach (i.e., ideally devoid of adjustable parameters) that includes the main physically relevant effects governing particle transport on the one hand, and that is amenable to numerical treatment at affordable computational expenses on the other. The approach proposed, based on ensemble statistics of stochastic particle trajectories, is validated by comparing/contrasting model predictions to available experimental data encompassing different particle dimensions. The comparison suggests that at low/moderate values of the flowrate the approach can yield an accurate prediction of the separation performance, thus making it a promising tool for designing device geometries and operating conditions in nanoscale applications of the DLD technique.

scholarly journals On the Three-Dimensional Structure of the Flow through Deterministic Lateral Displacement Devices and Its Effects on Particle Separation

Processes ◽  
2019 ◽  
Vol 7 (8) ◽  
pp. 498 ◽  
Author(s):  
Valentina Biagioni ◽  
Alessandra Adrover ◽  
Stefano Cerbelli
Keyword(s):  
Lateral Displacement ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Periodic Lattice ◽  
Separation Mechanism ◽  
Label Free ◽  
Deterministic Lateral Displacement ◽  
Slip Conditions ◽  
Flow Through ◽  
The Impact

Experiments have shown that a suspension of particles of different dimensions pushed through a periodic lattice of micrometric obstacles can be sorted based on particle size. This label-free separation mechanism, referred to as Deterministic Lateral Displacement (DLD), has been explained hinging on the structure of the 2D solution of the Stokes flow through the patterned geometry, thus neglecting the influence of the no-slip conditions at the top and bottom walls of the channel hosting the obstacle lattice. We show that the no-slip conditions at these surfaces trigger the onset of off-plane velocity components, which impart full three-dimensional character to the flow. The impact of the 3D flow structure on particle transport is investigated by enforcing an excluded volume approach for modelling the interaction between the finite-sized particles and the solid surfaces. We find that the combined action of particle diffusion and of the off-plane velocity component causes the suspended particles to migrate towards the top and bottom walls of the channel. Preliminary results suggest that this effect makes the migration angle of the particles significantly different from that obtained by assuming a strictly two-dimensional structure for the flow of the suspending fluid.

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.

Lateral obstacle avoidance control based on driving behavior recognition of the preceding vehicles in adjacent lanes

2020 ◽  
Vol 68 (10) ◽  
pp. 880-892
Author(s):  
Youguo He ◽  
Xing Gong ◽  
Chaochun Yuan ◽  
Jie Shen ◽  
Yingkui Du
Keyword(s):  
Obstacle Avoidance ◽  
Lateral Displacement ◽  
Longitudinal Velocity ◽  
Driving Behavior ◽  
Lateral Acceleration ◽  
Lateral Motion ◽  
Behavior Recognition ◽  
Dynamic Surface ◽  
Lane Changing ◽  
The Impact

AbstractThis paper proposes a lateral lane change obstacle avoidance constraint control simulation algorithm based on the driving behavior recognition of the preceding vehicles in adjacent lanes. Firstly, the driving behavior of the preceding vehicles is recognized based on the Hidden Markov Model, this research uses longitudinal velocity, lateral displacement and lateral velocity as the optimal observation signals to recognize the driving behaviors including lane-keeping, left-lane-changing or right-lane-changing; Secondly, through the simulation of the dangerous cutting-in behavior of the preceding vehicles in adjacent lanes, this paper calculates the ideal front wheel steering angle according to the designed lateral acceleration in the process of obstacle avoidance, designs the vehicle lateral motion controller by combining the backstepping and Dynamic Surface Control, and the safety boundary of the lateral motion is constrained based on the Barrier Lyapunov Function; Finally, simulation model is built, and the simulation results show that the designed controller has good performance. This active safety technology effectively reduces the impact on the autonomous vehicle safety when the preceding vehicle suddenly cuts into the lane.

scholarly journals Driven Pile Effects on Nearby Cylindrical and Semi-Tapered Pile in Sandy Clay

2021 ◽  
Vol 11 (7) ◽  
pp. 2919
Author(s):  
Massamba Fall ◽  
Zhengguo Gao ◽  
Becaye Cissokho Ndiaye
Keyword(s):  
Coupling Effect ◽  
Lateral Displacement ◽  
Bending Moment ◽  
Adaptive Mesh ◽  
Pile Driving ◽  
Arbitrary Lagrangian Eulerian ◽  
Axial Forces ◽  
Tapered Pile ◽  
Driven Pile ◽  
The Impact

A pile foundation is commonly adopted for transferring superstructure loads into the ground in weaker soil. They diminish the settlement of the infrastructure and augment the soil-bearing capacity. This paper emphases the pile-driving effect on an existing adjacent cylindrical and semi-tapered pile. Driving a three-dimensional pile into the ground is fruitfully accomplished by combining the arbitrary Lagrangian–Eulerian (ALE) adaptive mesh and element deletion methods without adopting any assumptions that would simplify the simulation. Axial forces, bending moment, and lateral displacement were studied in the neighboring already-installed pile. An investigation was made into some factors affecting the forces and bending moment, such as pile spacing and the shape of the already-installed pile (cylindrical, tapered, or semi-tapered). An important response was observed in the impact of the driven pile on the nearby existing one, the bending moment and axial forces were not negligible, and when the pile was loaded, it was recommended to consider the coupling effect. Moreover, the adjacent semi-tapered pile was subjected to less axial and lateral movement than the cylindrical one with the same length and volume for taper angles smaller than 1.0°, and vice versa for taper angles greater than 1.4°.

scholarly journals Integrated, Speckle-Based Displacement Measurement for Lateral Scanning White Light Interferometry

Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2486
Author(s):  
Gert Behrends ◽  
Dirk Stöbener ◽  
Andreas Fischer
Keyword(s):  
White Light ◽  
Lateral Displacement ◽  
Displacement Measurement ◽  
Accurate Information ◽  
White Light Interferometry ◽  
Fully Integrated ◽  
Speckle Correlation ◽  
Dsc Measurements ◽  
Scanning White Light Interferometry ◽  
The Impact

Lateral scanning white light interferometry (LSWLI) is a promising technique for high-resolution topography measurements on moving surfaces. To achieve resolutions typically associated with white light interferometry, accurate information on the lateral displacement of the measured surface is essential. Since the uncertainty requirement for a respective displacement measurement is currently not known, Monte Carlo simulations of LSWLI measurements are carried out at first to assess the impact of the displacement uncertainty on the topography measurement. The simulation shows that the uncertainty of the displacement measurement has a larger influence on the total height uncertainty than the uncertainty of the displacing motion itself. Secondly, a sufficiently precise displacement measurement by means of digital speckle correlation (DSC) is proposed that is fully integrated into the field of view of the interferometer. In contrast to externally applied displacement measurement systems, the integrated combination of DSC with LSWLI needs no synchronization and calibration, and it is applicable for translatory as well as rotatory scans. To demonstrate the findings, an LSWLI setup with integrated DSC measurements is realized and tested on a rotating cylindrical object with a surface made of a linear encoder strip.

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