3D droplet reconstruction from a single image to analyze surface wetting phenomena

Irregularly shaped droplets commonly occur in heat transfer, surface sciences, non-wetting textiles, and dew harvesting. However, characterizing 3D droplet geometries is often challenging and requires a large number of images taken from numerous orientations. Here, we present an entirely new method of surface wetting analysis using specular reflections of point source lights on a droplet to numerically solve the Young-Laplace equation. From this solution, we reconstruct the droplet in 3D from a single image, allowing us to quantify phenomena such as local contact angle, gravitational distortions, and surface tension, which are difficult or impossible to quantify with traditional methods such as goniometry. This method can then be applied to multi-droplet systems at regular intervals to analyze the dynamic change in these phenomena over long timescales.