Ideas from nature have often provoked materials scientists, who have made self-cleaning surfaces inspired by lotus leaves, for example, and adhesive feet for robots that can climb walls as geckos do. Now researchers have imitated water-striding insects, constructing a device that can skate at the interface between oil and water (ACS Nano, DOI: 10.1021/nn301550v). To do so they created a surface on the device’s legs that repels oil underwater.
Researchers had previously discovered that water striders’ legs work through the chemistry and physics of microprojections lined with nanogrooves on the bugs’ legs (Nature, DOI: 10.1038/432036a). Shutao Wang, of the Chinese Academy of Sciences, thought that he could use similar structures to solve a materials problem: Most materials that repel oil, known as oleophobic materials, don’t work if they get wet. Superoleophobic coatings that work when wet could keep bugs from sticking to car windshields, scientists think, and enable robots to move through and clean up oil spills.