Continuous particle separation in a microfluidic channel via standing surface acoustic waves (SSAW)

Area of Science:

• Microfluidics
• Acoustofluidics
• Particle Separation

Background:

• Continuous particle separation is crucial for various applications.
• Existing methods face limitations in efficiency and versatility.

Purpose of the Study:

• To introduce a novel method for continuous particle separation using standing surface acoustic wave (SSAW)-induced acoustophoresis.
• To demonstrate particle separation based on volume, density, and compressibility.

Main Methods:

• Utilized a microfluidic channel with a central sheath flow and side inlets for particle mixture.
• Generated a one-dimensional SSAW using parallel interdigital transducers (IDTs).
• Leveraged SSAW-induced acoustic forces to manipulate particle positions based on their physical properties.

Main Results:

• Particles were laterally separated within the microchannel based on their volume.
• Larger particles experienced greater axial acoustic forces, moving closer to the central pressure node.
• Achieved high separation efficiency with low power consumption.

Conclusions:

• The SSAW-based acoustophoresis method provides a simple and versatile approach for continuous particle separation.
• This technique is applicable to a wide range of particles, irrespective of their charge or optical properties.
• Demonstrated efficient, low-power particle separation based on physical characteristics.