Microfluidic Monodispersed Microbubble Generation for Production of Cavitation Nuclei

Area of Science:

• Materials Science
• Fluid Dynamics
• Acoustics

Background:

• Microbubbles act as cavitation nuclei, undergoing expansion, contraction, and collapse.
• Bubble collapse generates shockwaves, altering local shear forces and temperature, leading to material surface erosion, pitting, and reduced mechanical strength.
• Accurate modeling of cavitation phenomena necessitates control over bubble size and the generation of monodispersed bubbles.

Purpose of the Study:

• To develop a novel, low-cost microfluidic method for generating monodispersed microbubbles with controllable sizes.
• To investigate the relationship between microfluidic design, flow conditions, and microbubble characteristics.
• To provide a reproducible platform for cavitation research.

Main Methods:

• Utilized a novel T-junction microfluidic structure fabricated using CNC milling.
• Controlled two-phase flow dynamics via gas and liquid pressure ratios.
• Generated microbubbles with diameters significantly smaller than the channel width (e.g., 20 μm in a 100 μm channel).

Main Results:

• Successfully produced monodispersed microbubbles with controllable diameters (e.g., 20 μm).
• Achieved microbubble generation without high-resolution equipment or cleanroom facilities.
• Demonstrated that bubble size is controllable via pressure gradients and microgeometry.

Conclusions:

• The developed microfluidic method offers a cost-effective and reproducible approach for generating monodispersed microbubbles.
• This technique facilitates precise control over bubble size, crucial for advancing cavitation research and understanding material degradation.
• The method is suitable for applications requiring controlled cavitation nuclei generation.