Harvard researchers have created the most durable, super-slick and anti-corrosive steel surface-coating to date. This tough material can enhance the structural integrity, anti-corrosive characteristics and longevity of steel structures when it comes to engineering, as well as proving useful for other applications in fields such as medicine.
This new material, called Slippery Liquid-Infused Porous Surfaces (SLIPS), was developed by a team of researchers led by Joanna Aizenberg, who is the Amy Smith Berylson Professor of Materials Science, at the Wyss Institute for Biologically Inspired Engineering located at Harvard University.
Over the last fifty years numerous grades of steel have been developed and improved upon, but the enhancement of steel surfaces has been largely overlooked during this time, until now.
This material is made from coarse nano-porous tungsten oxide giving it the ability to repel liquid of any sort even after the material has withstood immense structural harm.
“We need surfaces to be textured and porous to impart fouling resistance but rough nano-structured 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,” explained Professor Aizenberg.
It has a very broad range of applications across various fields such as medicine, engineering and construction. The coating could be applied to steel medical instruments and devices like scalpels and implants, it could be used for 3D printer nozzles and micro-array devices and on a greater scale, in marine vessels, buildings and other structures.
The impact of bio-fuelling on ship hulls is an energy-expenditure problem the United States Navy deals with annually, spending tens of millions of dollars to clean-off barnacles, algae and other organisms which create drag and increase energy-usage. Once these contaminants are removed from the hull, environmentally damaging anti-fouling paints are reapplied to protect the ship.
This new steel material has great potential to provide a more cost-effective, cleaner and environmentally safer alternative. An alternative which could be adopted by not only The US Navy, but global shipping industries and others.
The steel we use today is still fairly susceptible to abrasion from sand and corrosion from all manner of liquids. These tools still run the risk of becoming contaminated, leading to deadly infections. This new steel surface coating minimises abrasion, corrosion and the risk of contamination.
Professor Aizenberg is aware that this revolutionary new steel material must be scalable without upsetting sector practices if it is to be embraced by businesses and organisations on a larger scale.
"I don't want to create another line that would cost millions and millions of dollars and that no one would adopt," Professor Aizenberg said.
This super-strong and slick steel surface coating was tested in a variety of ways to determine its resilience to abrasion and corrosion:
It was scratched with stainless steel screwdrivers and tweezers, diamond-tip scribers.
Relentlessly beaten with hundreds of thousands of unbreakable, very-heavy beads.
Next came liquid testing in which the researchers drenched the material in various liquids including water, highly corrosive material, oil, biological fluids comprising of blood & bacteria.
The results were astounding. As hoped the steel material repelled every last drop of liquid and demonstrated anti-biofouling performance, but not only this, the nano-porous tungsten oxide imbued the steel with extra-strength it would not otherwise have possessed, without the added coating.