Sheathless electrokinetic particle separation in a bifurcating microchannel.

Area of Science:

• Microfluidics
• Biotechnology
• Analytical Chemistry

Background:

• Particle separation is crucial in industry and academia.
• Existing electrokinetic methods often use dielectrophoresis with microelectrodes or insulators.
• These methods can be complex or limited in throughput.

Purpose of the Study:

• To develop a new, continuous, sheath-free electrokinetic particle separation technique.
• To utilize inherent wall-induced electrical lift for particle focusing and deflection.
• To establish a theoretical model for understanding size-based separation.

Main Methods:

• Implementing a bifurcating microchannel design.
• Applying electric fields to induce wall-induced electrical lift.
• Observing particle behavior and separation dynamics.
• Developing and validating a theoretical model for particle focusing and deflection.

Main Results:

• Demonstrated continuous, sheath-free particle separation based on size.
• Successfully focused particles towards the centerline using wall-induced electrical lift.
• Achieved size-dependent deflection of particles into different branch channels.
• Theoretical model showed good agreement with experimental observations.

Conclusions:

• The developed method offers an efficient, sheath-free approach for continuous particle separation.
• Wall-induced electrical lift is a viable mechanism for size-based particle manipulation in microchannels.
• The technique has potential for parallel or cascade operation to enhance throughput or resolution.