“Our slippery steel is orders of magnitude more durable than any anti-fouling material that has been developed before,” said Aizenberg. “So far, these two concepts – mechanical durability and anti-fouling – were at odds with each other. We need surfaces to be textured and porous to impart fouling resistance but rough nanostructured coatings are intrinsically weaker than their bulk analogs. This research shows that careful surface engineering allows the design of a material capable of performing multiple, even conflicting, functions, without performance degradation.”
 

This material holds promise for a wide range of applications, such as non-fouling medical devices and tools including scalpels and implants, 3D printing nozzles, and marine and building applications.
 

The team had to find out ways to ensure that the structure of the steel maintained its anti-fouling capability without undergoing any mechanical degradation due to the new surface. The team grew an ultrathin film that was made up of hundreds of thousands of nanoscale rough, tungsten-oxide islands on a steel surface using an electrochemical technique.
 

“If one part of an island is destroyed, the damage doesn’t propagate to other parts of the surface because of the lack of interconnectivity between neighboring islands,” said Alexander B. Tesler, former postdoctoral fellow at SEAS, current research fellow at Weizmann Institute of Science in Israel and the paper’s first author.
 

“This island-like morphology combined with the inherent durability and roughness of the tungsten oxide allows the surface to keep its repellent properties in highly abrasive applications, which was impossible until now.”