Unveiling the complex morphologies of sessile droplets on heterogeneous surfaces

Droplets exhibiting a myriad of shapes on surfaces are ubiquitous in both nature and industrial applications. In high-resolution manufacturing processes, e.g., semiconductor chips, precise control over wetting shapes is crucial for production accuracy. Despite the high demand for describing droplet wetting shapes and their transformations across a wide range of applications, a robust model for precisely depicting complex three-dimensional (3D) wetting droplet shapes on heterogeneous surfaces remains elusive. Herein, we fill this gap by developing a universal, high-precision model that accurately describes wetting shapes, including those with polygonal baselines and irregular footprints. Our model reveals the intricate wetting morphologies beyond the classic Young’s law and Cassie-Baxter-Wenzel models. Besides, it aligns quantitatively with physical simulations for various droplet volumes. This work provides a potential method to achieve highly complex morphologies of droplets via low-cost beforehand design of the surfaces, thereby opening up potential applications in 3D printing, printed electronics, and microfluidics.