Numerical Modeling Using Immersed Boundary-Lattice Boltzmann Method and Experiments for Particle Manipulation under...

Area of Science:

• Fluid dynamics
• Acoustic manipulation
• Microfluidics

Background:

• Standing surface acoustic waves (SSAW) are used for microparticle manipulation.
• Accurate simulation of microparticle behavior in acoustic fields is crucial for microfluidic applications.
• The Immersed Boundary-Lattice Boltzmann Method (IB-LBM) offers a robust framework for simulating complex fluid-particle interactions.

Purpose of the Study:

• To simulate and analyze the motion of microparticles in a microchannel driven by SSAW.
• To develop and validate a numerical model for predicting microparticle trajectories and steady-state positions.
• To investigate the influence of particle properties and SSAW parameters on microparticle behavior.

Main Methods:

• Utilized the Immersed Boundary-Lattice Boltzmann Method (IB-LBM) with custom C code for simulations.
• Developed a mapping mechanism to accurately implement acoustic forces within the numerical model.
• Fabricated a microfluidic device and conducted experimental validation using lithographic techniques.

Main Results:

• Microparticles with a positive acoustic contrast factor migrate towards SSAW-induced pressure nodes.
• Particle trajectory and final position are influenced by particle properties (size, density, compressibility).
• Simulated steady-state particle placements showed excellent agreement with experimental results.

Conclusions:

• The IB-LBM is a validated tool for simulating SSAW-driven microparticle manipulation in microchannels.
• Controlled positioning of microparticles at desired locations (e.g., channel centerline or sidewalls) is achievable by manipulating SSAW pressure nodes.
• This work provides a foundation for designing advanced microfluidic systems utilizing acoustic manipulation for particle sorting and handling.