To increase the nucleate boiling efficiency, many nucleate boiling experiments have been conducted and could get brilliant and challcngcablc results. A consensus was that CHF and heat transfer were affected by a modified heating surface which change the micro roughness, thcrmophysical properties of heating surface, or the wcttability. Of the many parameters, the wettability study is regarded as the most powerful factor. For finding the optimized condition at the nucleate boiling (high heat transfer and high CHF), we design the special heaters to examine how two materials, which have different wettabilitics, affect the boiling phenomena. The special heaters have several types of hydrophobic patterns which have the precise size because they were made by MEMS techniques on the silicon oxide surface. In the experiments with patterned surface, hydrophobic dots lead to an early bubble inception and induce the better heal transfer. These experiments are compared with classic and recent models for bubble inception. The all experiments arc conducted under the saturated pool boiling condition with distilled water at 1 atm pressure. The peculiar Teflon (AF1600) is used as the hydrophobic material. The hydrophilic part is performed by silicon oxide through the furnace procedure. The experiments using the micro-sized patterns and milli-sizcd patterns arc performed, and the results are compared with the reference surface. These mixed-wcttability studies are expected to induce the development of the nucleate boiling condition.
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