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arXiv · 1909.04253

Mapping micron-scale wetting properties of superhydrophobic surfaces

Dan Daniel·Chee Leng Lay·Anqi Sng·Corryl Jing Jun Lee·Darren Chi Jin Neo·Xing Yi Ling·Nikodem Tomczak
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Abstract

There is a huge interest in developing super-repellent surfaces for anti-fouling and heat transfer applications. To characterize the wetting properties of such surfaces, the most common approach is to place a millimetric-sized droplet and measure its contact angles. The adhesion and friction forces can then be indirectly inferred from the Furmidge's relation. While easy to implement, contact angle measurements are semi-quantitative and cannot resolve wetting variations on a surface. Here, we attach a micrometric-sized droplet to an Atomic Force Microscope cantilever to directly measure adhesion and friction forces with nanonewton force resolutions. We spatially map the micron-scale wetting properties of superhydrophobic surfaces and observe the time-resolved pinning-depinning dynamics as a droplet detaches from or moves across the surface.

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Dan Daniel, Chee Leng Lay, Anqi Sng, Corryl Jing Jun Lee, Darren Chi Jin Neo, Xing Yi Ling, Nikodem Tomczak. 2019-09-10. Mapping micron-scale wetting properties of superhydrophobic surfaces. https://doi.org/10.1073/pnas.1916772116

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