Continuous hydrophoretic separation and sizing of microparticles using slanted obstacles in a microchannel

Area of Science:

• Microfluidics
• Biotechnology
• Particle Science

Background:

• Microparticle manipulation is crucial for various applications, including diagnostics and drug delivery.
• Existing methods often require external fields, limiting portability and biocompatibility.

Purpose of the Study:

• To develop a novel microfluidic method for microparticle separation and sizing.
• To demonstrate power-free and biocompatible particle control using hydrophoresis.

Main Methods:

• Utilized slanted obstacles in a microchannel to generate a microstructure-induced pressure field (hydrophoresis).
• Exploited the resulting lateral pressure gradient to deflect and arrange microparticles.
• Separated and sized polystyrene microbeads based on their diameter.

Main Results:

• Achieved complete separation of 9 and 12 micrometer (µm) polystyrene microbeads.
• Discriminated polystyrene microbeads with diameter differences as small as 7.3%.
• Measured bead diameters with high accuracy, comparable to laser diffraction methods.

Conclusions:

• Hydrophoresis offers a unique approach for microparticle manipulation without external fields.
• The developed method is power-free, biocompatible, and suitable for integrated microfluidic devices.
• This technique presents a new opportunity for advanced particle control in microfluidics.