Assessment of Lagrangian Modeling of Particle Motion in a Spiral Microchannel for Inertial Microfluidics

Abstract

Inertial microfluidics is a promising tool for a label-free particle manipulation for microfluidics technology. It can be utilized for particle separation based on size and shape, as well as focusing of particles. Prediction of particles’ trajectories is essential for the design of inertial microfluidic devices. At this point, numerical modeling is an important tool to understand the underlying physics and assess the performance of devices. A Monte Carlo-type computational model based on a Lagrangian discrete phase model is developed to simulate the particle trajectories in a spiral microchannel for inertial microfluidics. The continuous phase (flow field) is solved without the presence of a discrete phase (particles) using COMSOL Multi-physics. Once the flow field is obtained, the trajectory of particles is determined in the post-processing step via the COMSOL-MATLAB interface. To resemble the operation condition of the device, the random inlet position of the particles, many particles are simulated with random initial locations from the inlet of the microchannel. The applicability of different models for the inertial forces is discussed. The computational model is verified with experimental results from the literature. Different cases in a spiral channel with aspect ratios of 2.0 and 9.0 are simulated. The simulation results for the spiral channel with an aspect ratio of 9.0 are compared against the experimental data. The results reveal that despite certain limitations of our model, the current computational model satisfactorily predicts the location and the width of the focusing streams.

Computational inertial microfluidics: a review

“…74 Similar to serpentine channels, spiral microchannels have been frequently used for the separation of bio-particles and cells. [75][76][77][78][79][80] If the size of particles in spiral channels is less than a particular threshold (a < 0.07D H ), the effect of the drag forces overcomes the inertial forces and traps particles in their vortex streamlines (Fig. 8B).…”

Systematic Review: Microfluidics and Plasmodium

“…There is a wide range of methods for simulating microfluidics using a variety of software. One of the more popular and used software is COMSOL Multiphysics version 5.5 (COMSOL, Boston, MA, USA) with the microfluidics add-on module [52][53][54][55].…”

Tape’n roll inertial microfluidics

“…Straight channel with arc-shaped groove arrays is another structure capable of 3D focusing of particles [37]. Curvedchannels in different formats, including spiral [19,24,38,39] and serpentine [23,26,40,41], have been investigated both experimentally and numerically. Curved channel shape introduces two transverse vortices as secondary flow.…”

“…Recently, Rasooli et al introduced computational modeling approach by using Crank-Nicolson temporal integrator to study inertial migration of particles in spiral microchannels. [39] Here, we implement the fourth order Runga-Kutta technique to solve the differential equation. The particle tracking algorithm is explained in detail in the supplementary file.…”