Leaf-inspired material makes different liquids flow in opposite ways

A surface with 3D-ratchet structures that allow liquids of different surface tensions and to spread in different directions. This idea was inspired by Araucaria leaves City University of Hong Kong
One leaf inspired a new material that can alter the flow of liquids. Fluids with different properties flow in opposite directions due to the leaf's scaly texture, even though one direction is upwards.

Araucaria is an evergreen tree genus that includes some called monkey puzzles. It has spiky cylindrical leaves with smaller scale-like segments called Ratchets. Zuankai Wang