On the motion of a liquid marble sliding on the liquid-infused surface

Liquid marbles—droplets encapsulated by particles—offer unique non-wetting properties for applications in microfluidics and surface engineering. Liquid marbles gliding over a wetted surface exhibit significant contact angle hysteresis, which reduces frictional resistance and enhances their sliding ability. However, their dynamic behavior on wetted surfaces remains underexplored. Consequently, designing surfaces to prevent particle contamination requires clear design principles and the use of additional droplets to cleanse the surface and maintain its cleanliness. This study focuses on wettability, elastic behavior, dynamic behavior of liquids, and their interaction with surface characteristics. The experimental results categorize the movement process of liquid marble on a wetted surface into three stages based on the movement state: the shedding stage, the deformation stage, and the sliding stage. During the process, the contact friction force F f2 generated between the liquid marble and the lubricating surface is proportional to the change in the contact angle Δθ of the liquid marble ( F f2 ~ Δθ ). The viscous force dominates the forces affecting the marble's movement during the peeling and deformation stages. The deformation will exhibit compression and rebound phenomena for liquid marbles with a volume of V  > 30 μL. Surface tension governs the movement of liquid marbles during the sliding stage. The air film on the marble's surfaces reduces the contact area with the solid surface, resulting in a more pronounced non-wetting effect. Incorporating hydrophobic particles within a droplet enhances its surface tension, and the capillary action between the particles and the droplet enables adhesion to the surface. This prolongs deformation and improves stability during the movement process.