Deciphering the Evolution of Inertial Migration in Serpentine Channels

Area of Science:

• Fluid dynamics
• Microfluidics
• Biomedical engineering

Background:

• Serpentine channels utilize inertial and secondary flows for particle focusing and separation.
• Unclear inertial migration mechanisms in these channels hinder their application in diagnostics and drug screening.

Purpose of the Study:

• To model and elucidate the effect of secondary flow on particle migration in serpentine channels.
• To refine the understanding of inertial migration mechanisms for improved particle separation.

Main Methods:

• Direct numerical simulation (DNS) to compute inertial lift.
• Lagrangian particle tracking (LPT) to analyze particle migration.
• Experimental validation of the numerical model for microparticle migration.

Main Results:

• Particle migration in serpentine channels exhibits a two-stage process.
• Increased secondary flow accelerates the second migration stage and slows the first.
• Established guidelines for high-resolution particle separation by analyzing parameter effects.

Conclusions:

• The study clarifies the inertial migration mechanism in serpentine channels.
• Findings provide a foundation for inertial particle separation in microfluidic devices.
• Dimensionless analysis enables the separation of particles of various sizes, considering flow resistance.