Executive Summary : | Microfluidics has become a crucial field in recent years due to its portability, low power consumption, and short assay times. It is used in point-of-care diagnostic and environmental monitoring devices, which require manipulation of particles, such as particle focusing, separation, and isolation within a fluid sample. These particles can be micro-contaminants, blood cells, vesicles, cancer cells, and bacteria. Inertial focusing, a technique that involves the lateral migration of randomly distributed particles at well-defined positions, has gained significant attention due to its precise manipulation, simple structure, and high throughput. However, the underlying physics involved in inertial focusing is still unclear due to the difficulty in capturing the physics of multiple particle interactions in a microchannel. The current proposal aims to numerically investigate the physical mechanism of lateral migration of particles in the microchannel using the immersed boundary method (IBM) to simulate particle motion and the lattice Boltzmann method (LBM) to solve fluid flow. The Immersed boundary-lattice Boltzmann method (IB-LBM) is a combination of IBM and LBM, focusing on understanding the effect of initial particle positions, axial distance, viscosity ratio, particle size, and Reynolds number on equilibrium positions. |