Copper-based high-efficiency condensation heat transfer interface consisting of superhydrophobic hierarchical microgroove and nanocone structure

Abstract

Currently, developing high-efficiency condensation heat transfer (CHT) interfaces via known or unknown copper micro/nanofabrication technologies with practical prospects attracts great interest due to its values in developing next generation small-space high-heat-flux dissipation technologies. Here, we report that CHT performance of copper surface can be enhanced via skillful combination of microgroove skeleton and superhydrophobic nanocone covering, which can be fabricated by wire electrical discharge machining, electroless copper plating and thiol modification technologies. We first explore the influence of groove width, groove depth and fin width to condensation heat and mass transfer and obtain the optimized microgroove structure. Subsequently, such structure is demonstrated to have more superior CHT performance than the micropillar with comparable geometric parameters. Further, we verify that the superhydrophobic hierarchical structure has the best performance, which shows maximally 82.9% enhancement in CHT coefficient as compared to the flat hydrophobic copper, while the optimized microgroove structure performs better than the nanocone. Their structure-property relationships are rationalized according to the fundamentals of condensation mass and heat transfer. Clearly, this work not only helps understand how micro- and nanoscale structures rationally design to enhance condensation heat transfer but also develop high-performance vapor chambers for electronic cooling.