Extended Data Fig. 5: Self-cleaning of the surface in fog.

The optical image sequences show the self-cleaning of the armoured superhydrophobic surface in fog. The red arrows indicate the dust particles (collected from air in Chengdu, China) on the surface. The yellow circle highlights how the droplet captures the dust particle and rolls off of the surface. The images were recorded with a Photron SA5 high-speed camera fitted with a macro lens at a frame rate of 5,000 frames per second. The surface was placed on an aluminium alloy cold plate with a tilt angle of approximately 45°. The cold plate was controlled at around 2 °C, and the fog was at an ambient temperature with a high relative humidity of around 95%. The fog consisted of a cloud of water droplets (average radius 3.5 μm) suspended in air, generated using an ultrasonic humidifier.