Superomniphobic Material Vigorously Repels All Fluids
Dr. Anish Tuteja has developed a coating that will repel just about any liquid.
You may have heard of oleophobic coatings (which reduce smudges on your touchscreen) or hydrophobic coatings (which repel water). Working with a team at the University of Michigan, he’s developed a new coating for material that will repel both Newtonian and non-Newtonian fluids of just about any kind. They’re calling it superomniphobic.
According to Dr. Tuteja, the key to making fluids bounce off a material is to trap pockets of air between the fluid at the surface. This starts as a chemistry problem (you want a material with low surface energy) but quickly becomes a physics problem. “With chemistry we can cause water to bead up but not oil,” he says. “To get to the next step you have to design the geometry or the shape of the coating.”
To create the coating, the team takes a polymer solution and applies an electric field to it. By tuning the concentration of the polymer solution, they can change how the solution breaks up into microscopic droplets. These droplets are then deposited on the surface, and Dr. Tuteja says they can coat any material.
The result is a hierarchical texture, where a highly porous surface is itself made up of nanopores. There are so many millions of tiny pockets of air trapped under the droplet that the fluid and the surface barely come into contact at all. Dr. Tuteja says they’ve left samples submerged for up to two months. They come out completely dry.
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http://www.wired.com/design/2013/02/superomniphobicexpialidocious/
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enough for me
