Elasto-capillary wetting on deformable solids

Elasto-capillary wetting is a fluid-structure interaction (FSI) phenomenon, wherein the solid deformation is driven by the capillary forces at fluid-fluid interfaces. Elasto-capillary wetting is relevant in various micro- and nano-scale applications, such as inkjet printing, microfabrication, microfluidics, and biophysics. Here, we develop a high-fidelity elasto-capillary FSI model that can simulate systems with three immiscible fluids and a nonlinear elastic solid. We use this model to investigate static and dynamic elasto-capillary wetting problems, including the spontaneous droplet transport of both single and multi-component fluids on solids with space-varying stiffness (droplet durotaxis). Our findings indicate that the dynamics of droplets can be effectively controlled by varying the wettability and solid stiffness. Our results suggest more efficient ways to transport droplets in various applications, such as self-cleaning of surfaces and energy harvesting.