Dielectrophoretic separation/classification/focusing of microparticles using electrified lab-on-a-disc platforms

Area of Science:

• Microfluidics
• Biophysics
• Analytical Chemistry

Background:

• Microparticle separation, classification, and focusing are critical in microfluidics.
• Label-free methods utilize inherent particle properties, with dielectrophoresis (DEP) being a key technique.
• Centrifugal microfluidic devices use centrifugal forces for fluid and particle manipulation.

Purpose of the Study:

• To investigate the combined effects of dielectrophoretic and centrifugal forces on microparticle trajectories.
• To develop and analyze an integrated system for microparticle manipulation in microfluidic devices.

Main Methods:

• Numerical analysis of microparticle movement in a rectangular microchannel with planar electrodes on a centrifugal platform.
• Investigation of coordinate-based parameters (offsets, tilting angles) and operational parameters (voltage, channel width, electrode configuration).
• Evaluation of the system's efficiency in classifying red blood cells, platelets, and yeast cells.

Main Results:

• Enhanced particle focusing achieved at lower rotation speeds and higher electric fields.
• Demonstrated ability to guide particles to desired routes and control focusing width.
• Successful classification of biological microparticles, including differentiating live/dead yeast cells.

Conclusions:

• The integrated centrifugal-dielectrophoresis system offers a novel, sheath-flow-free method for microparticle focusing and classification.
• The system provides high-efficiency throughput and ease of operation compared to traditional DEP devices.
• This approach enables precise manipulation and separation of diverse microparticles.