Fun fact – lotus leaves naturally repel water but not oil. Sounds simple but this design may be the answer to cleaning oil spills at sea.
Engineers at the University of Ohio have used the lotus as inspiration and flipped it on its head, developing a fine mesh that water can pass through, leaving oil behind.
Using nanotechnology they cover stainless steel mesh with a polymer embedded with molecules of surfactant — the stuff that gives cleaning power to soap and detergent. A fine dusting of silica nanoparticles is then sprayed onto the mesh to create a randomly bumpy surface and layered the polymer and surfactant on top.
The prototype is small, however Bharat Bhushan, Ohio Eminent Scholar states that the product can easily be scaled up. Effectively this mesh can catch oil spills like a net, leaving the water behind. Even better news due to the materials used to produce the mesh Bhushan predicts that it could cost less than a dollar per square foot.
This discovery is just part of the research Bhushan is working on, along with postdoctoral researcher Philip Brown. Together they have looked at a variety of natural surfaces from butterfly wings to shark skin to discover their unique attributes.
However Brown states “Nature reaches a limit of what it can do. To repel synthetic materials like oils, we need to bring in another level of chemistry that nature doesn’t have access to.” Nanotechnology is looking to be a great complementary solution and their reverse lotus leaf design could be the answer for many countries that struggle with cleaning costly oil spills.
