High-Efficiency Inertial Separation of Microparticles Using Elevated Columned Reservoirs and Vortex Technique for...

Area of Science:

• Biomedical Engineering
• Microfluidics
• Cancer Diagnostics

Background:

• Circulating tumor cells (CTCs) are vital biomarkers for cancer diagnosis and prognosis.
• Vortex separation is a promising label-free method for CTC isolation in lab-on-a-chip systems.
• Previous vortex separation designs faced limitations in efficiency and processing time.

Purpose of the Study:

• To enhance the efficiency and capacity of vortex-based CTC isolation.
• To investigate the impact of chip geometry modifications on particle separation.
• To develop an improved method for CTC capture and analysis.

Main Methods:

• Redesigning chip geometry with elevated columned reservoirs (ECRs) for improved particle capture.
• Utilizing numerical simulations to analyze the contribution of the third axis to separation.
• Employing microparticles (20 μm and 8 μm) to represent CTCs and smaller blood cells.
• Developing an upgraded injection system and an air bubble purging method.

Main Results:

• Achieved an average separation efficiency of ~80% ± 8.3% for microparticles, a 14% increase.
• Obtained a purity of 61% in microparticle separation.
• Demonstrated over three times higher capacity for retaining orbiting particles compared to previous designs.
• Successfully characterized the new chip geometry and validated its performance.

Conclusions:

• The redesigned height-variable chip with ECRs significantly improves microparticle separation efficiency and capacity.
• This enhanced vortex separation method offers a more effective solution for CTC isolation.
• The developed techniques facilitate robust operation of microfluidic devices for cancer research.