Surface-Energy Patterning of Metals for High-Demand, Energy-Efficient, mm-Scale Cooling Applications

The present work attempts to showcase the effectiveness of surface-energy patterning (wettability patterning) in thermal management applications. It is focused on exploring two different routes of engineering: the investigation of a conceptual design leading to a proof-of-concept system in the very first stages of research and the revamping of an existing device by applying new technology to it with the purpose of increasing its performance. The motivation behind this work is drawn from the great potential of surface-energy patterning to provide a platform that harnesses surface tension forces in order to transport fluids in a pumpless and rapid manner, in fact faster and more efficiently than porous media. Knowing that thermal management is not only about maintaining the proper temperature conditions for certain components, but also doing so with the least amount of energy spent, it is imperative to investigate surface energy patterning as a method of fabricating energy-efficient cooling devices. A novel active cooling system composed of a surface-energy-patterned aluminum heat sink is assembled and examined first, providing proof of concept and quantitative thermal performance measurements. This system is then taken a step further by examining various parameters that affect the performance of the aforementioned system and establishing the theoretical basis for system optimization. A modified design stemming from the theoretical considerations is finally presented and tested, increasing both system stability and performance. Finally, the focus is shifted to improving the efficiency of the vapor chamber heat spreader by replacing certain key components inside it with surface energy patterning. Namely, wettability patterning is introduced on the condenser side showing competitive performance and gravity independent operation.