Mask-Enabled Topography Contrast on Aluminum Surfaces

Area of Science:

• Materials Science
• Surface Engineering
• Nanotechnology

Background:

• Patterned surfaces with wettability contrast are crucial for advanced liquid transport in electronics thermal management, self-cleaning, and anti-icing.
• Aluminum (Al) surfaces are widely used in thermal applications, but methods for creating topography-patterned wettability contrast on Al are limited.

Purpose of the Study:

• To demonstrate an easy and scalable method for creating topography-patterned wettability contrast on aluminum surfaces using blade-cut masking.
• To quantify the accuracy of topographic pattern resolution, surface roughness, wettability, and thermal emissivity of the patterned Al surfaces.

Main Methods:

• Utilized blade-cut vinyl mask templates and a commercial lacquer resin as an etch resist.
• Employed etching processes to create topographic contrast on aluminum surfaces.
• Characterized wettability using contact angle goniometry and thermal emissivity using infrared thermography.

Main Results:

• Achieved wettability contrast from <5° to 80° (etched vs. smooth) and 150° to 120° (etched vs. smooth with hydrophobic coating).
• Demonstrated enhanced droplet shedding on superhydrophobic regions of striped patterned surfaces during condensation.
• Mapped topography-mediated thermal emissivity contrast, with etched regions at ε ≈ 0.65 and smooth regions at ε ≈ 0.26.

Conclusions:

• The blade-cut masking method offers a scalable route to fabricate complex topography-patterned aluminum surfaces with controlled wettability and emissivity.
• These patterned surfaces show potential for applications in vapor chamber thermal rectification, radiative cooling, and high-temperature phase change processes.