Atmospheric Water Vapor Condensation on Ultra-short Pulsed Laser Surface-Processed Copper

Condensation, a ubiquitous phenomenon with applications ranging from power generation to climate control in buildings, features a complex interplay of surface properties, heat transfer and fluid dynamics. In recent years, Ultra-short Pulsed Laser Surface Processing (ULSP) has emerged as a powerful tool to engineer surface structures with unparalleled precision and control over scales of practical relevance. This study explores how ULSP-structured surfaces are poised to alter condensation studies and applications. One of the primary advantages of ULSP-structured surfaces is their ability to tailor surface topography scalably both at the micro and nano scales. These engineered structures serve as nucleation sites for condensation, influencing the mode of condensation. Herein, high-aspect-ratio (tall) microstructures of O(~100μm) are fabricated via ULSP on copper plates. The plates are characterized for their roughness and wettability when they reveal superhydrophilic properties. The resulting substrates are then characterized for condensation, wherein uniform film-wise condensation is observed throughout the experiment duration. Furthermore, the condensation heat transfer coefficient (CHTC) is compared against a mirror-finish Teflon-coated Cu substrate via gravimetric estimations. Interestingly, the ULSP plates are found to have similar condensation performance to mirror finish hydrophobic samples, or outperform them at almost all experimental scenarios.