Making a superoleophobic surface requires some ingenuity. In particular, such surfaces must be created with two traits. First, they need a particular “roughness” that creates air pockets between the solid surface and the oil droplets. Second, they require a chemical coating with low surface energy.

To achieve roughness, the Ohio State researchers embedded tiny particles of silica (the main ingredient in sand) into their plastic. To do so, they applied the particles to the polypropylene surface using a liquid that could dissolve the top layer of plastic. For the chemical coating, they used a compound of fluorine, called fluorosilane, to coat the rough polypropylene they created.

Part of the novelty of this approach is how durable the surface is, Dr. Bhushan said. Many previous attempts relied on weakly bonded coatings to achieve roughness. This polypropylene is so durable, he added, because the silica structures used to create roughness are embedded in the plastic, rather than sitting on top of it.

The difference is akin to melting down the glaze on a doughnut, embedding sprinkles in it and letting the glaze harden again, versus sticking sprinkles onto the doughnut using frosting. With the first method, the sprinkles are lodged in the glaze. With the second, the frosting could come off, taking the sprinkles with it.

Embedding silica with a solution is a clever approach, said Siddarth Srinivasan, a researcher of fluid mechanics and surfaces at Harvard University who was not involved in the research. “Their technique is so simple, and easy to scale up,” he said.

Scaling up is something the Ohio State researchers had in mind. It’s feasible to adapt this process to the commercial production of shampoo bottles, Dr. Bhushan said.