Deterministic Lateral Displacement: Challenges and Perspectives

Abstract

The advent of microfluidics in the 1990s promised a revolution in multiple industries, from healthcare to chemical processing. Deterministic Lateral Displacement (DLD) is a continuous-flow microfluidic particle separation method discovered in 2004 that has been applied successfully and widely to the separation of blood cells, yeast, spores, bacteria, viruses, DNA, droplets, and more. DLD is conceptually simple and can deliver consistent performance over a wide range of flow rates and particle concentrations.Despite wide use and in-depth study, DLD has not yet been fully understood or fully optimised, with different approaches to the same problem yielding varying results. We endeavour here to provide an up-to-date expert opinion on the state-of-art and current fundamental, practical, and commercial challenges as well as experimental and modelling opportunities. Since these challenges and opportunities arise from constraints on hydrodynamics, fabrication and operation at the micro-and nano-scale, we expect this article to serve as a guide for the broader micro-and nanofluidic community to identify and address open questions in the field.

A pair of particles in inertial microfluidics: effect of shape, softness, and position

“…9 Lab-on-a-chip techniques using external force fields include optical tweezers, 10 dielectrophoresis, 11 magnetophoresis, 12 and acoustophoresis. 13 On the other hand, deterministic lateral displacements at low Reynolds number using appropriately placed pillars 14 and inertial microfluidics [15][16][17][18][19][20] exploit internal hydrodynamic forces to achieve particle separation. In contrast to common microfluidic lab-on-a-chip devices in which fluid inertia is negligible, inertial microfluidics operates in an intermediate range between Stokes and turbulent regimes, where flow is still laminar.…”

Brownian Sieving Effect for Boosting the Performance of Microcapillary Hydrodynamic Chromatography. Proof of Concept

“…Therefore, it could become competitive with other size-based separation techniques, such as, deterministic lateral displacement. 38 …”

Advancements in Throughput, Lifetime, Purification, and Workflow for Integrated Nanoscale Deterministic Lateral Displacement

“…Device lifetime is fundamental to deployment and applicability of deterministic lateral displacement and has been a critical challenge for improving DLD. [ 19,25 ] The advantage of DLD as a continuous separation process is diminished by clogging, which renders an effective device lifetime after which sample output and/or separation efficiency attenuate. Previous work with nanoDLD has used off‐chip prefiltering, surface functionalization, and on‐chip, prearray structural filters to ensure device survival.…”

“…A recent perspective article by A. Hochstetter et al. specifically states “For nano‐DLD, scaling up flow rates is the biggest challenge,” and more broadly identifies “To unlock its full potential, nano‐DLD must overcome limitations in flow rates, chip lifetime, functionality, and ease of operation.” [ 25 ] Addressing limitations in each of these areas is necessary to enable adoption of nanoDLD as a nanoscale particle separator, and there are several key engineering design factors that require consideration to achieve this goal as shown in Figure 1b. The key challenge of improved flow rates is addressed by implementing array density scaling for i ‐nanoDLD, achieving ≈83 arrays mm −2 of active area with 31 160 arrays on a single chip and a record throughput of up to ≈17 mL h –1 at 7 bar.…”