Evaporative Wicking Phenomena on Nanotextured Surfaces

As modern electronics become miniaturized with high power, thermal management for electronics devices has become significant. This motivates the implementation of new cooling solutions to dissipate high-heat levels from high-performance electronics. Evaporative cooling is one of the most promising approaches for meeting these future thermal demands. Thin-film evaporation promotes heat dissipation through the phase change process with minimal conduction resistance. In this process, it is important to design surface structures and corresponding surface properties that can minimize meniscus thickness, increase liquid–vapor interfacial area, and enhance evaporation performances. In this study, we investigate thin-film evaporation by employing nanotextured copper substrates for varying thermal conditions. The liquid spreading on the nanotextured surfaces is visualized using a high-speed imaging technique to quantify evaporative heat transfer for various surfaces. The permeability is calculated using an enhanced wicking model to estimate the evaporation effect combined with the mass measurements. Then, infrared (IR) thermography is employed to examine two-dimensional temporal temperature profiles of the samples during the evaporative wicking with a given heat flux. The combination of optical time-lapse images, evaporation rate measurements, and temperature profiles will provide a comprehensive understanding of evaporation performances using textured surfaces.