Computational evaluation of a microfluidic device for sorting multiple distinctive circulating tumor cells using single disproportionate deterministic lateral displacement array

Circulating tumor cells (CTCs) are the cells, found in extremely few numbers in human blood branching out from the primitive tumor location, carried further by the circulation of blood passage, thus recognized as a major crucial bio-indicator for early and promising cancer cure and diagnosis. Deterministic lateral displacement (DLD), being a tried and tested passive technique depending on uneven bifurcation of laminar flow traversing through a structured array of microposts, is a promising method in isolating cells of differing sizes. In this study, a microfluidic device with a single sample inlet, two symmetrical buffer inlets and housing an asymmetric DLD array, has been presented that clearly distinguishes two distinctive CTCs from White blood cells (WBCs) using continuous flow through a single DLD array. Making use of a computation software COMSOL Multiphysics 5.4, simulated design of the proposed microfluidic device has been analyzed taking into account an infused blood sample comprising of massive CTCs branching from lung cancer site, CTCs branching from prostate cancer site and comparatively smaller WBCs of diametric sizes 22.5 µm, 10.64 µm and 12 µm correspondingly. The obtained response after simulation study shows that the proposed device design separates out two distinct CTCs from WBCs through corresponding specified outlets at elevated sample inflow rate of 22 × 10^–6 kg/s and Re of 22.47 thus functioning appreciably at elevated value of throughput. The horizontal and vertical gaps between microposts have been optimized such that the DLD based device imposes minimal resistive imposition to the movement of cells, maintains unaltered pressure points distribution surrounding microposts and at outlets, amplifies throughput and provides superlative isolation efficiency and purity of extracted CTCs and WBCs.