Regulating the Self‐Propulsion of Liquid Marbles on a Water Pool

Abstract Regulating droplet motion with minimal energy input and adhesion loss holds significant promise for efficient liquid transportation. One efficient strategy involves the design of non‐sticking droplets capable of regulated self‐propulsion. However, achieving precise control over the self‐propelling trajectory while maintaining non‐sticking property is challenging. Here, a series of non‐sticking solvent droplets that self‐propel on the water pool are developed. These droplets are covered with omniphobic nanoparticles to become non‐sticking, namely liquid marble. It is found that the droplet self‐propelling behavior, such as velocity and trajectory (i.e., polygonal, circular, spinning, and random), differed based on the liquid property (surface tension, solubility in water, volatility, etc.) owing to the branched underlying mechanism. The self‐propelling driving force is not confined to the solute capillary force but extends to other forces, including the non‐solute capillary, vapor‐induced recoiling, and electrostatic force. The understanding of the self‐propelling dynamics offers a basis for regulating the trajectories of self‐propelling droplets of solvents from rectilinear to circular, random, stop‐and‐go motion, with a modulated transition time. Even liquid selective wettability at the perimeter of the water pool influenced the self‐propelling behavior of the prepared liquid marbles. Thereafter, such liquid marbles are successfully explored in cargo transportation.