The research, published recently in Langmuir and conducted by groups at Rice University and the University of Edinburgh as part of the Rice-Edinburgh Strategic Collaboration Awards program, demonstrates how cost-effective vinyl masking techniques can produce surfaces with high-resolution wettability contrast, paving the way for improved phase-change heat transfer applications.
The research team developed a novel technique using blade-cut vinyl masking and commercially available lacquer resin combined with scalable physical and chemical surface treatments to create patterned aluminium surfaces. These surfaces exhibit distinct wettability contrasts, significantly improving the droplet shedding during condensation. The patterns, with feature sizes as small as 1.5 mm, offer a range of wettability behaviours — from superhydrophobic to hydrophilic — depending on the treatment.
“This method represents an important step in tailored surface engineering,” said Daniel J. Preston, assistant professor of mechanical engineering at Rice and a co-corresponding author of the paper along with Geoff Wehmeyer, assistant professor of mechanical engineering at Rice, and Daniel Orejon from the University of Edinburgh. “By enabling precise control over surface wettability and thermal properties, we are opening new doors for scalable manufacturing of advanced heat transfer surfaces.”
The research employed a multistep methodology to develop and analyse the patterned aluminium surfaces. Vinyl masks were first applied to polished aluminium substrates, followed by a two-step etching process that created micro- and nanotextured zones. The team then used advanced imaging techniques to characterise the patterns’ resolution and wettability properties. To evaluate performance, condensation visualisation experiments demonstrated enhanced droplet shedding on the patterned surfaces compared to homogeneous ones. Additionally, thermal emissivity mapping using infrared thermography revealed significant contrasts in emissivity between smooth and textured regions, highlighting the surfaces’ potential for advanced thermal management applications.
“Aluminium is widely used in thermal management devices like heat exchangers due to its high conductivity, low density and low cost,” said Wehmeyer. “Our method adds a new dimension to its functionality by integrating surface patterning that is both cost-effective and scalable, allowing engineers to fine-tune the condensation heat transfer. This work brought together expertise from Edinburgh and Rice to develop and characterise these advanced surfaces.”
