Microvelia normally walks on water, but under threat it sprays a low–surface-tension liquid to lower local interfacial tension and slides rapidly, about 5 times faster than walking. We analyze the underlying (Marangoni) mechanism and develop a mechanism-based actuator that leverages the same principle.

High-speed imaging shows that a single raindrop striking infected wheat liberates thousands of Puccinia triticina spores and simultaneously forms an air vortex ring that lifts and carries them away. The vortex increases spores’ height and range, and a characterized model predicts their trajectories, implying raindrop impacts can transport pathogens beyond the leaf boundary layer for long-distance spread.