Deterministic separation of suspended particles in a reconfigurable obstacle array

Abstract

We use a macromodel of a flow-driven deterministic lateral displacement (DLD) microfluidic system to investigate conditions leading to size-separation of suspended particles. This model system can be easily reconfigured to establish an arbitrary orientation between the average flow field and the array of obstacles comprising the stationary phase (forcing angle). We also investigate the effect of obstacle size using two arrays with different obstacles but same surface-to-surface distance between them. In all cases, we observe the presence of a locked mode at small forcing angles, in which particles move along a principal direction in the lattice until a locked-to-zigzag transition takes place when the driving force reaches a critical angle. We show that the transition occurs at increasing angles for larger particles, thus enabling particle separation at specific forcing angles. Moreover, we observe a linear correlation between the critical angle and the size of the particles that could be used in the design of microfluidic systems with a fixed orientation of the flow field. Finally, we present a simple model, based on the presence of irreversible interactions between the suspended particles and the obstacles, which describes the observed dependence of the migration angle on the orientation of the average flow.

Deterministic Lateral Displacement-Based Separation of Magnetic Beads and Its Applications of Antibody Recognition

“…At the maximum forcing angle, the 20 µm magnetic beads are almost evenly divided into three outlets because the forcing angle has exceeded the critical angle, and the particles change from the displacement mode to the zigzag mode. It was reported that the critical angle increased with the increase of the diameter of the particles [26], which is consistent with our results. The critical angle for 10 µm beads, 20 µm beads and 40 µm beads are 10 • -15 • , 15 • -20 • and >20 • , respectively.…”

“…We show two types of particles in Figure 3, small (blue) ones, critical angles θ 1 and large (red) ones, critical angles θ 2 . The critical angle of larger diameter particles is larger than that of smaller diameter particles [26]. So, the θ 2 is assumed to be greater than the θ 1 in the model.…”

Hydrodynamic lift forces on solutes in a tilted nanopillar array: A computer simulation study

“…Deterministic lateral displacement (DLD) method for particle separation in microfluidic devices makes the best use of surface structures. It has gained widespread acceptance in recent years due to its high resolution and robust separation .…”

Gravity driven deterministic lateral displacement for suspended particles in a 3D obstacle array

“…in the direction along the cylindrical obstacles. We have shown in previous work that macroscopic DLD models can facilitate detailed research on the particle motion inside the obstacle array 3,9,10 . Therefore, we designed a macroscopic setup that allows for direct visualization of the particles moving through the array of long cylindrical posts and to set at an arbitrary orientation with respect to the driving force (gravity).…”

“…It has been shown in previous work that macroscopic DLD models can facilitate detailed research on the particles motion inside the obstacle array 10 18 19 20 . Therefore, we designed a macroscopic setup that allows for direct visualization of suspended particles moving through an array of long cylindrical posts.…”