The carnivorous pitcher plant, Nepenthes, can capture insects to meet their fundamental nutrient needs through their peristome. The peristome can be completely wetted by water and then form a slippery liquid film, which induces insects to “aquaplane” on it. This gives inspiration for designing well-known slippery directional continuous transportation surfaces.

There is a special micron multi-scale wedge-shaped blind hole array structure on peristome surface. This structure spontaneously forms gradient Taylor capillary rise, which makes the peristome surface have the ability of water unidirectional rapid and continuous transportation. Under the action of this force, the water can continuously fill in the wedge-shaped blind hole and evenly spread to form a liquid film. Moreover, this structure will firmly hold water in its original position so that the peristome surface will remain super-wet and slippery constantly. The insect cannot escape and easily slide into the cage to be preyed on.

Based on the inspiration gained from the peristome structure of Nepenthes, researchers have fabricated a variety of surfaces equipped with unidirectional liquid transport function. The application of such designs on the bipolar plates of fuel cell will lead to higher efficiency of gas utilization and water removal, which can significantly improve the performance of fuel cell.