UNS: Experimental and Theoretical Investigation of Thin Film Evaporation in Superhydrophobic-Superhydrophilic Hybrid Micro\Nanotextures

University Of North Texas, Denton TX

Investigators

Abstract

Because liquid evaporation takes away a large amount of heat from a surface, rapid evaporation is desirable. The research team will fabricate new types of surfaces from which thin liquid films can evaporate faster than in a typical boiling process. As a consequence, these surfaces enable removing heat at very high rates which is demanded in many industrial applications. Not only graduate students but also K-12 students from the Dallas area will be involved in this project. Thin film evaporation in capillary wicking structures can potentially yield higher heat transfer rates as compared to those of nucleate boiling. To further enhance the film evaporation heat transfer, the PI proposes to explore a novel avenue with the help of electro-wetting on dielectric (EWOD) to initiate and sustain thin film evaporation in micro/nano porous bi-wick structures decorated on hot spot surfaces. The PI will first develop multi-scale textured surfaces with micro- and nano-scale structures with treatments to make them super-hydrophobic or super-hydrophilic. The EWOD fluidic operations will be used to generate precisely controlled liquid volume on the surface. The project will be concentrated on detecting fluid meniscus distributions and wetting flow dynamics, using micro-PIV (particle imaging velocimetry) on different surface structures to determine the interdependency of the surface texturing on the wicking dynamics and thin film thickness in the presence of high heat fluxes and the effect of surface texturing on heat transfer rates.