Droplet Directional Transport and Heat Transfer Enhancement Characteristics of Fishbone-Shaped Supersuperhydrophobic-Superhydrophilic Pattern

Abstract

As a high phase changes latent heat and heat transfer efficiency, the vapor chamber is widely used in the heat dissipation of electronic devices. In order to further improve the heat transfer efficiency and reduce the thermal resistance in the same volume. In this work, a superhydrophobic (151.0º) - superhydrophilic (2.1º) fishbone-shaped wedge pattern on droplet transportation was prepared. The superhydrophilic region of the branch can collect a wide range of droplets, and the main path is for long-distance transportation of droplets to the center. The structural parameters of the pattern were analyzed by orthogonal experiment and response surface analysis to understand the behavior characteristics of the droplet in the hydrophilic-superhydrophobic binary plane motion, and the optimal design parameters were obtained by response surface analysis. The velocity of optimal pattern is up to 275mm/s, which is higher than all orthogonal design patterns. The maximum enhancement of velocity, mass point and peak value compared with top2 pattern is 19.4%, 5.7% and 23.4% respectively. Applying the optimal pattern to the condensation section of the vapor chamber can optimize the thermal resistance by 63.3%, and smaller patterns can further increase the equivalent thermal conductivity by 23.0%.

Keywords: Wedge-patterned, Laplace pressure, Supersuperhydrophobic-superhydrophilic region, Response surface methodology, Vapor chamber