Numerical Investigation on the Effects of Cell Deformability and DLD Microfluidic Device Geometric Parameters on the Isolation of Circulating Tumor Cells

Deterministic Lateral Displacement (DLD) microfluidic devices provide a simple and passive separation method for the isolation of Circulating Tumor Cells (CTCs) in blood samples based on their biophysical properties. In the present paper, the hydrodynamic motion of deformable cells in the DLD microfluidic device is simulated using the Fluid-Solid Interaction (FSI) approach, Finite Element Method (FEM), and dynamic mesh by employing COMSOL Multiphysics software. The effect of particle size, inlet velocity, the tilted angle of posts, and their shape on the separation mechanism is evaluated and the optimal case is introduced. It is demonstrated that deformability has a crucial role in the lateral motion of cells in the device. It is revealed that the final y-displacement of WBC, CTC-2, and CTC-1 is -15 μm, -28 μm, and -40 μm, respectively, indicating that the deformability affects the displacement and trajectory of cells at the same initial fluid velocity. The results show that soft particles are affected more by fluid velocity in comparison with stiff ones, especially at Re = 0.1. The present results propose a DLD device with arrays of I-shaped micro-posts in which the lateral displacement of deformable cells is larger compared to previously introduced shapes of micro-posts.