Force and Velocity Analysis of Particles Manipulated by Toroidal Vortex on Optoelectrokinetic Microfluidic Platform

Area of Science:

• Physics
• Microfluidics
• Biomedical Engineering

Background:

• Rapid electrokinetic patterning (REP) is a technique for dynamic particle manipulation in biomedical applications.
• Prior research on REP primarily focused on particles smaller than 5 μm.

Purpose of the Study:

• To investigate the manipulation of larger polystyrene particles (3-11 μm) using a REP platform.
• To analyze the effects of electrothermal vortex synergy forces on particle motion.

Main Methods:

• Utilized a microfluidic channel with ITO conductive glass plates for REP.
• Conducted numerical simulations to study particle motion under varying laser power, AC voltage, and frequency.
• Performed experimental validation of simulation findings.

Main Results:

• Observed a competition between drag force (bulk flow recirculation) and trapping force (surface aggregation).
• Increased laser power expanded bulk flow circulation and reduced surface trapping.
• Higher laser power increased particle velocity, especially for smaller particles.
• Particle trapping frequency decreased with increasing particle size.

Conclusions:

• REP effectively manipulates larger microparticles, extending its applicability in microfluidics.
• Laser power is a critical parameter influencing particle dynamics in REP.
• Findings provide insights into cell-level motion behavior for biomedical applications.