Study on the discrete dielectrophoresis for particle-cell separation

Area of Science:

• Biophysics
• Microfluidics
• Biomedical Engineering

Background:

• Dielectrophoresis (DEP) is a label-free technique for manipulating cells and particles.
• Microfluidic devices offer precise control for biological separations.
• Efficient separation of microparticles from blood cells is crucial for diagnostics and sample preparation.

Purpose of the Study:

• To develop and validate a microfluidic device for separating polystyrene particles from red blood cells using discrete dielectrophoretic force.
• To investigate the influence of voltage magnitude and duty cycle on cell deflection and velocity.
• To assess the enrichment factor and separation efficiency of the proposed method.

Main Methods:

• Utilized a microfluidic device with interdigitated electrodes and a microchannel.
• Generated discrete dielectrophoretic force by adjusting the applied voltage duty cycle.
• Employed tilted electrodes to alter red blood cell trajectories.
• Analyzed red blood cell deflection and velocity under positive dielectrophoresis.

Main Results:

• Achieved particle enrichment greater than 150 times.
• Demonstrated a maximum separation efficiency of 97% for a 1:2000 particle-to-cell ratio in concentrated samples.
• Successfully prevented microchannel clogging through optimized voltage and duty cycle control.

Conclusions:

• Discrete dielectrophoretic force in a tailored microfluidic device enables high-efficiency separation of microparticles from red blood cells.
• The method is robust, preventing clogging and achieving significant enrichment.
• This technology holds promise for biomedical sample preparation and diagnosis, including rare cell isolation.