Drops impacting inclined fibers.

Mats of fibers are often used to capture liquid drops, such as in filters or in fog's nets. It is desired to optimize the efficiency of capture, in particular in the limit of drops larger than the fibers, for which filters remain highly permeable. Here we show that the efficiency of capture is dramatically increased by tilting the fibers: then, the velocity V* below which a drop is fully captured is made much larger; moreover, the tilt maximizes the liquid volume left on the fiber when the impact velocity exceeds V*.