Harvard researchers develop way to make 'super-steel'

Researchers at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) have developed a new steel surface coating that makes the world's most important engineering and construction material stronger, safer and more durable.

"Our slippery steel is more durable than any anti-fouling material that has been developed before," Harvard University quoted professor Joanna Aizenberg and Amy Smith Berylson, professor of materials science and core faculty member of the Wyss Institute for Biologically Inspired Engineering, as saying in a statement.

Developed by Aizenberg's team, the new surface coating -- Slippery Liquid-Infused Porous Surfaces (SLIPS) -- is made from rough nanoporous tungsten oxide. It is the most durable anti-fouling and anti-corrosive material to date, capable of repelling any kind of liquid even after sustaining intense structural abuse, according to the varsity.

"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," Aizenberg said.

According to Alexander B. Tesler, former post doctoral fellow at SEAS, "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".

While various grades of steel have been developed over the past 50 years, steel surfaces have remained largely unchanged -- and unimproved.

Electrochemical deposition is already a widely used technique in steel manufacturing, according to Aizenberg.

"I don't want to create another line that would cost millions and millions of dollars and that no one would adopt," Aizenberg said. The goal, she said, is to be scalable but not disruptive to current industry practices.

The new SLIPS-enhanced steel has been described in the journal Nature Communications.