Research Projects

Futuristic electronic cooling systems demand the removal of high heat fluxes in confined spaces. The vapor chamber is well-suited for these applications. In vapor chambers, both evaporation and condensation occur within very narrow gaps, direct experimental validation is challenging. Though some progress has been made using wetting modifications on the evaporator and condenser surfaces, there is still significant potential to improve phase-change efficiency through patterned wettability. This research proposes novel surface engineering strategies to address these challenges. A major innovation is the integration of superhydrophobic cones on the condenser surface, oriented toward the boiling surface. These structures enable early detachment of nucleated vapor bubbles and promote directional vapor transport, which suppresses bubble collapse and film formation under high heat flux. The cone tip size and geometry will be optimized. To facilitate condensate return, shape-gradient hydrophilic channels will be incorporated into the condenser surface and connected to superhydrophilic guiding pins. These patterns will be optimized through experimental studies and numerical simulations. Wedge-shaped superhydrophilic surfaces will aid in transporting condensate via Laplace pressure gradients. It directs liquid toward the evaporator for efficient recirculation. Wettability gradients will be fine-tuned through detailed condensation studies. These wettability patterns and modifications will be incorporated using a laser ablation technique and chemical etching process. The contact angle of the surface will be measured using a goniometer. The surface morphology of the different wettable locations will be analyzed through SEM images, optical profilometry, etc. The research includes experimental and numerical approaches. Boiling and condensation studies will be conducted separately to optimize wettability patterns and cone configurations respectively. The transportability of liquid drops and the rate of condensation will be considered for optimizing wettability patterned surfaces. From boiling studies, the boiling curve and the critical heat flux will be analyzed using the recorded temperature and heat flux data. Numerical simulations using ANSYS Fluent will evaluate boiling, condensation, and overall vapor chamber efficiency. A vapor chamber will be fabricated using the best-performing designs and tested under varying heat flux and filling ratio conditions to determine optimal performance. The expected outcomes include a comprehensive understanding of boiling behavior with early bubble detachment helped by superhydrophobic cones, and condensation behavior on patterned wettable surfaces. Optimized wettable designs will ensure high condensation rates and effective liquid return. The work will also lead to validated numerical models and the development of advanced wickless vapor chamber heat sinks for high-performance next-generation electronic cooling systems.