Superbiphilic Laser-Microengineered Surfaces with A Self-Assembled Monolayer Coating for Exceptional Boiling Performance

The rapid advancement of engineering systems has spurred the search for innovative thermal management solutions. Boiling, as a phase-change heat transfer method, has shown promise in heat dissipation, but non-functionalized surfaces struggle with increasing cooling demands. To improve heat dissipation efficiency across different heat loads, functionalized surfaces with tailored wettability have been proposed. Separately, superhydrophilic and superhydrophobic surfaces each offer benefits and drawbacks in boiling applications but combining them on a single biphilic surface simultaneously harnesses their advantages. In this study, laser-functionalized copper surfaces with spatially tailored wettability are developed by combining two-step laser texturing with a self-assembled monolayer coating, while focus is placed on the impact of the size and pitch of superhydrophobic spots. The developed functionalized surfaces exhibit exceptional boiling performance with heat transfer coefficients up to 299 kW m-2 K-1, a 434% enhancement over untreated surfaces. Optimal ratios of superhydrophilic and superhydrophobic areas and optimal spot pitch are identified. Additionally, varying behavior at different heat flux levels is observed, emphasizing the importance of considering thermal loads when determining the optimal surface pattern. This advancement in performance, along with the rapid and cost-effective functionalization process, represents a significant breakthrough for enhanced thermal management applications. In this study, laser-functionalized copper surfaces with spatially tailored wettability are developed by combining two-step laser texturing with a self-assembled monolayer coating as an innovative thermal management solution. These biphilic surfaces exhibit intentionally varied local superhydrophobicity and superhydrophilicity and exceptional pool boiling performance with heat transfer coefficients up to 299 kW m-2 K-1, a 434% enhancement over untreated surfaces.image

Automated summary

This study develops laser-functionalized copper surfaces with spatially tailored wettability through two-step laser texturing and self-assembled monolayer coating, achieving remarkable enhancement in boiling performance. The optimal ratios of superhydrophilic and superhydrophobic areas and optimal spot pitch are determined experimentally.