Congratulations to Samuel Cruz for successfully defending his PhD on capillary-driven condensation for heat transfer enhancement in steam power plants.

Sam’s thesis proposes a way to model, fabricate, optimize, demonstrate the proof-of-concept, and measure the heat transfer coefficient for a novel condensation approach which we term capillary-driven condensation. The method consists of a hierarchical structure consisting of a wicking structure overlaid with a porous hydrophobic membrane. To demonstrate the viability of this condensation method, we fabricate the structure with highly-defined geometry utilizing silicon micro-fabrication techniques. The result is a surface which is able to constrain a thin film of condensate within the wicking structure while the top condensation surface appears dry. The thickness of this layer and geometry of the membrane can be rationally designed to maximize the heat transfer coefficient even beyond dropwise condensation. Heat transfer measurements reveal enhancements of up to 4x which are still being confirmed. The results from this thesis elucidate the physics and demonstrate the promise of capillary-driven condensation surfaces for heat transfer applications.