Tuning particle inertial separation in sinusoidal channels by embedding periodic obstacle microstructures

Area of Science:

• Microfluidics
• Biotechnology
• Biomedical Engineering

Background:

• Inertial microfluidics relies on fluid dynamics and channel geometry for particle manipulation.
• Existing channel designs (straight, expansion-contraction, spiral, serpentine) have limitations.
• Innovative designs combining geometries can enhance microfluidic device performance.

Purpose of the Study:

• To explore the influence of periodic concave and convex microstructures in sinusoidal channels on particle inertial focusing and separation.
• To develop a cascaded microfluidic device for rare cell separation using these enhanced channels.

Main Methods:

• Embedding periodic concave and convex microstructures within sinusoidal microfluidic channels.
• Investigating the impact of these microstructures on Dean flow and particle behavior.
• Designing and testing a cascaded device integrating two sinusoidal channels with concave obstacles for rare cell separation.

Main Results:

• Concave obstacles significantly enhanced Dean flow, enabling tunable flow ranges for inertial focusing and separation.
• The cascaded device demonstrated outstanding separation performance for polystyrene beads and T47D breast cancer cells.
• Purity enhancement reached 3 to 4 orders of magnitude for rare cell samples with low initial cancer cell ratios.

Conclusions:

• Embedding microstructures in microfluidic channels offers design flexibility for inertial microfluidic devices.
• This approach provides a feasible method for creating serial processing units for high-performance particle and cell separation.
• The developed device shows significant potential for rare cell isolation and diagnostic applications.