Microfluidic shape-based separation for cells and particles: recent progress and future perspective

Area of Science:

• Microfluidics
• Biotechnology
• Materials Science

Background:

• Conventional size-based particle separation methods are limited.
• Shape-based separation is crucial for isolating particles with identical volumes but different morphologies, essential for biomedical applications like pathological cell isolation.
• Microfluidic platforms offer a powerful yet underdeveloped strategy for shape-based separation.

Purpose of the Study:

• To provide a comprehensive overview of recent progress in microfluidic platforms for shape-selective separation.
• To critically analyze both passive and active microfluidic techniques for shape discrimination.
• To highlight advancements, challenges, and future directions in shape-based microfluidic separation.

Main Methods:

• Review of passive microfluidic systems: deterministic lateral displacement, pinched flow fractionation, inertial, and viscoelastic microfluidics.
• Review of active microfluidic systems: dielectrophoresis, magnetophoresis, optophoresis, and acoustophoresis.
• Analysis of underlying mechanisms, technological advancements, and experimental/computational approaches for shape sensitivity.

Main Results:

• Recent advancements show high purities exceeding 95% and shape-based sorting efficiencies above 90%.
• Throughput rates vary from microliters to milliliters per minute, depending on device configuration.
• Techniques exploit hydrodynamic interactions or external fields to modulate particle trajectories based on geometric anisotropy.

Conclusions:

• Shape-based microfluidic separation is a promising strategy for high-precision particle isolation in diagnostics, therapeutics, and materials science.
• Challenges include modeling complex particle behaviors (rotation, alignment, deformability) and the need for integrated control and optimization.
• Future directions involve advancing scalable, high-precision shape-based separation techniques.