The Rapid Motion of the Leidenfrost Droplet Fired by a Laser

Traditional optofluidic droplet manipulation suffers from low transport efficiency due to the drag of surface tension. This study introduces laser-driven Leidenfrost droplets to achieve rapid, directional transport, with the total acceleration a up to ∼60 mm/s²-approximately triple that of Leidenfrost droplets without a laser. Both higher laser energy and stronger light absorption by the droplet enhance the transport efficiency of Leidenfrost droplets. The kinetic model elucidates that the droplet's rapid motion driven by the laser is attributable to a shift in the droplet's center of mass, induced by the nucleation of plasmonic bubbles. The displacement of the droplet's center of mass generates a driving torque, enhancing droplet internal flow and the vapor film beneath the droplet asymmetry, thereby increasing motion propulsion. This study lays the foundation for efficient light-driven droplet transport, offering valuable insights for advancing the practical application and control of Leidenfrost droplets.