Continuous-flow Ferrohydrodynamic Sorting of Particles and Cells in Microfluidic Devices

Area of Science:

• Biotechnology
• Microfluidics
• Nanotechnology

Background:

• Traditional cell and particle separation methods can be complex, costly, and require specific labeling.
• Ferrofluids, which are stable suspensions of magnetic nanoparticles, offer unique properties for manipulation under magnetic fields.

Purpose of the Study:

• To develop and characterize a novel, label-free sorting scheme for simultaneous separation of microparticles and live cells.
• To demonstrate the efficacy of ferrohydrodynamics in achieving size-dependent particle and cell separation.

Main Methods:

• Utilized ferrofluid hydrodynamics, leveraging magnetic buoyancy forces generated by external magnetic fields.
• Designed, modeled, fabricated, and characterized a microfluidic sorting device.
• Tested the system with fluorescent polystyrene microparticles, Escherichia coli, and Saccharomyces cerevisiae.

Main Results:

• Achieved simultaneous separation of microparticles and two distinct cell species (E. coli and S. cerevisiae).
• Demonstrated size-dependent deflection of particles and cells from laminar flow paths.
• Evaluated sorting throughput and efficiency of the ferrohydrodynamics-based system.

Conclusions:

• Ferrohydrodynamics provides a simple, low-cost, and label-free approach for particle and cell sorting.
• The developed sorting scheme shows promise for various applications in biotechnology and diagnostics.
• The technique enables efficient spatial separation based on magnetic buoyancy-induced deflections.