Leidenfrost propulsion on symmetric textured surfaces via spontaneous symmetry breaking

The Leidenfrost effect allows a gas film to form between a high-temperature substrate and a volatile liquid, resulting in a highly mobile drop. Previous research has shown that the surface texture needs to break the spatial symmetry to enable self-propulsion. Here, we demonstrate that spontaneous symmetry breaking in the gas-liquid flow above the texture generates substantial self-propulsion forces, driving drops on symmetric textured surfaces. Using a model of hydrodynamically coupled driven oscillators and computational fluid dynamic simulations, we show that drops are propelled by the pressure field of the vapor. We analyze the influence of drop size, temperature, and structural parameters of the substrate on the propulsion velocity. Furthermore, we observe similar self-propulsion in liquid nitrogen, ethanol, and liquid rings, indicating broad applicability. These findings highlight the importance of dynamic symmetry breaking of the gas-liquid interface in driving large-scale liquid motion and provide a potential path for efficient thermal-mechanical energy conversion.