Size-selective separation of micro beads by utilizing secondary flow in a curved rectangular microchannel

Area of Science:

• Fluid dynamics
• Microfluidics
• Particle separation

Background:

• Secondary flow in curved channels is typically considered unfavorable.
• Microscale fluid behavior differs significantly from macroscale phenomena.

Purpose of the Study:

• To demonstrate and explain the microscale benefit of secondary flow in curved microchannels.
• To achieve size-selective separation and sorting of micro-beads using secondary flow.

Main Methods:

• Numerical analysis of velocity distribution in cross-sectional planes.
• Experimental visualization of micro-bead trajectories.
• Investigating the impact of bead shape uniformity and inlet conditions.

Main Results:

• Successful separation and sorting of micro-beads based on size.
• Detailed explanation of the physical mechanism driving size-selective separation.
• Demonstration of dynamic trajectories for various micro-bead types.

Conclusions:

• Secondary flow in curved microchannels can be harnessed for beneficial micro-particle manipulation.
• Understanding flow dynamics is crucial for optimizing microfluidic separation processes.
• Bead shape and inlet conditions significantly influence separation efficiency.