Enhancing Spontaneous Droplet Motion on Structured Surfaces with Tailored Wedge Design

Spontaneous liquid transport has a wide variety of applications, including fog harvesting, microfluidics, and water-oil separation. Understanding of the droplet movement dynamics on structured surfaces is essential for enhancing the transport performance. In this work, a theoretical model describing the movement process of droplets on surfaces with prescribed wedge shapes is developed. Agreement is observed between the predictions from the model and experimental results. Through theoretical analysis and quantitative comparison between the transport performance of different wedge shapes, the factors affecting the movement process are identified and guidelines for wedge shape optimization for spontaneous droplet transport are provided.