Using lateral dispersion to optimise microfluidic trap array efficiency

TL;DR

This paper explores how manipulating lateral dispersion in microfluidic trap arrays can significantly improve trap filling efficiency, combining numerical modeling with preliminary experimental validation.

Contribution

It introduces a novel approach to enhance trap filling by promoting lateral dispersion through optimized flow angles or spatial disorder, improving efficiency without complex inlet/outlet modifications.

Findings

Optimized geometries increase trap filling efficiency.

Lateral dispersion can be enhanced by oblique flow or trap disorder.

Preliminary experiments support the numerical predictions.

Abstract

Microfluidic trapping arrays have proven to be efficient tools for various applications that require working at the single-cell level, such as cell-cell communication or fusion. Although several hydrodynamic trapping devices have already been optimised, two-dimensional (2D) single-layer trapping arrays with high trap densities remain partially inefficient. Specifically, many traps remain empty, even after prolonged injection, which drastically reduces the number of samples available for post-treatment. These unfilled traps result from the symmetrical nature of the flow around the traps, and breaking this symmetry enhances capture efficiency. In this study, we use a numerical approachto show that optimal geometries can significantly increase filling efficiency and a preliminary experimental test confirming our approach is provided. We show that these improvements are achieved by promoting lateral dispersion of particles, facilitated either through an optimised oblique flow or by introducing disorder into the spatial arrangement of traps without specific inlet/outlet adjustment.