Lateral-driven continuous dielectrophoretic microseparators for blood cells suspended in a highly conductive medium

Area of Science:

• Biomedical Engineering
• Microfluidics
• Cell Separation Technologies

Background:

• Dielectrophoresis (DEP) is a powerful technique for manipulating cells in microfluidic devices.
• Traditional DEP methods often require precise control over the conductivity of the suspension medium, limiting practical applications.
• Continuous separation of blood cells, particularly red blood cells (RBCs) and white blood cells (WBCs), remains a challenge in microfluidic systems.

Purpose of the Study:

• To develop and validate lateral-driven continuous dielectrophoretic (DEP) microseparators for efficient RBC and WBC separation.
• To demonstrate the practical application of DEP for blood cell separation without the need for conductivity control.
• To analyze the performance of divergent and convergent microseparator designs.

Main Methods:

• Utilized lateral DEP forces generated by angled planar interdigitated electrodes within microfluidic channels.
• Employed a simplified line charge model for theoretical analysis, validated against simulation and experimental data.
• Conducted experiments using dilute whole blood with a conductivity of 17 mS cm(-1) and a 2 MHz, 3 Vp-p AC voltage.

Main Results:

• The divergent microseparator achieved continuous separation of 87.0% RBCs and 92.1% WBCs within 5 minutes.
• The convergent microseparator demonstrated higher RBC separation (93.6%) but lower WBC separation (76.9%) under identical conditions.
• The developed DEP microseparators effectively separated blood cells without requiring manipulation of the suspension medium's conductivity.

Conclusions:

• Lateral-driven continuous DEP microseparators offer a practical and efficient method for separating RBCs and WBCs from whole blood.
• The technology overcomes critical limitations of conventional DEP devices by eliminating the need for conductivity control.
• This advancement holds significant potential for point-of-care diagnostics and other biomedical applications requiring rapid cell separation.