THE’lotus effect it is the ability that some plants have – like the they shake or “mist tree”, the lotus and the cabbage – to “self-clean” its leaves thanks to details super-hydrophobic properties due to molecular microstructures and nanostructures present on the leaves themselves assisted by a waxy layer which makes the leaves extremely waterproofso much so that when they come into contact with water it runs away leaving them completely dry.
What is the lotus effect, the phenomenon that makes leaves hydrophobic
The hydrophobic property of these leaves is due to the union of two effects: one physical structure composed of microstructures And nanostructures, and a waxy coating. The microstructures and nanostructures ensure that the water does not have a flat surface to adhere to, minimizing contact with the leaf. The waxy coating, similar to candle wax, is naturally repellent to water and helps repel it. The result? Water forms tiny spheres which slide away easily, taking with them the impurities deposited on the leaf.
Because these plants need water-repellent leaves
Nature has done many experiments, and only the best “designs” survive. Plants such as scotano, lotus and cabbage live in different environments, but they have all developed this property for three main reasons:
- Cleaning the leaves: these plants have large leaves, which work like “solar panels” to absorb the light necessary for photosynthesis. However, dust and debris can reduce their efficiency. The water that runs off also takes the dirt with it, keeping the leaves clean and ready to capture as much light as possible.
- Protection from mold and bacteria: in humid environments, retaining water can encourage the growth of mold and bacteria, which are dangerous for the health of the plant. Thanks to their hydrophobia, these leaves prevent water from stagnating, reducing the risk of infections.
- Prevention of freezing damage: for some plants such as Scotano, this property is crucial to avoid the formation of ice during cold nights, preventing the freezing of water which could otherwise damage the leaf tissues.
The application of the lotus effect in “self-cleaning” fabric technology
The ability of leaves to stay dry has also inspired several technological applications which represent very interesting examples of biomimicry. Paints, fabrics and “self-cleaning” coatingsfor example, exploit the same principle as hydrophobic plants to repel water and dirt, thus creating “stain-resistant” fabrics or materials.
This proves useful even in sectors we wouldn’t expect: aviation, for example. During the winter, ice that forms on aircraft wings is a serious hazard and requires systems de-icing complex and expensive, often chemical-based. Creating coatings similar to those found in lotus or scotan leaves could revolutionize the way we protect aircraft, preventing the formation of ice with natural, safer and more sustainable methods.
