Acoustofluidics-Assisted Coating of Microparticles

Area of Science:

• Materials Science
• Chemical Engineering
• Nanotechnology

Background:

• Microparticles are versatile materials used in diverse applications like drug delivery and diagnostics.
• Surface coating enhances microparticle functionality, offering benefits such as controlled release and improved stability.

Purpose of the Study:

• To propose and demonstrate a conformal coating method for microparticles using a positively charged polyelectrolyte (polyallylamine hydrochloride, PAH).
• To investigate the efficiency and uniformity of microparticle coating via an acoustofluidic microchip compared to batch methods.

Main Methods:

• Utilized an acoustofluidic microchip to create multiple laminar streams of PAH solution and microparticles.
• Employed traveling surface acoustic waves to guide microparticles through the streams for rapid, conformal coating.
• Investigated the effect of microchannel width and PAH concentration on zeta potential.

Main Results:

• Achieved rapid coating of microparticles using the microfluidic approach, outperforming traditional batch methods.
• Demonstrated more uniform zeta potentials for microparticles coated via the microfluidic method.
• Observed charge reversal and increased zeta potential with increasing microchannel width or PAH concentration for unfunctionalized microparticles.

Conclusions:

• The acoustofluidic microchip provides an efficient and rapid method for conformal microparticle coating.
• This microfluidic technique yields more uniform surface charge distribution, crucial for controlled applications.
• The study highlights the potential of acoustofluidics for tailored microparticle surface modification.