Large-scale Generation of Patterned Bubble Arrays on Printed Bi-functional Boiling Surfaces

Area of Science:

• Surface science
• Heat transfer
• Nanomaterials

Background:

• Controlling bubble nucleation, growth, and departure is crucial for understanding boiling phenomena and improving nucleate boiling heat transfer.
• Existing methods often lack the precision to tune these dynamics effectively.

Purpose of the Study:

• To introduce a novel bi-functional heterogeneous surface structure capable of tuning bubble nucleation, growth, and departure dynamics.
• To demonstrate enhanced heat transfer performance using these engineered surfaces.

Main Methods:

• Fabrication of heterogeneous surfaces by printing hydrophobic polymer dot arrays followed by hydrophilic ZnO nanostructure deposition using microreactor-assisted nanomaterial deposition (MAND).
• Utilizing wettability contrast between hydrophobic and hydrophilic regions for controlled bubble behavior.
• Examining bubble dynamics at elevated heat flux and performing pool boiling experiments.

Main Results:

• Demonstrated tunable control over bubble nucleation, growth, and departure dynamics.
• Achieved aligned and patterned bubble formation with tunable departure frequency and diameter for the first time.
• Fabricated a 6-inch wafer-scale heterogeneous surface.
• Observed up to a 3X enhancement in heat flux at the same surface superheat compared to a bare stainless steel surface.

Conclusions:

• The developed bi-functional heterogeneous surfaces offer precise control over bubble dynamics during boiling.
• This novel surface engineering approach significantly enhances nucleate boiling heat transfer performance.
• The fabrication method is scalable and demonstrates potential for advanced thermal management applications.