Electrodeposited TO films on a variety of surface geometries and steel grades
The surface coating, made from rough nanoporous tungsten oxide, 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.
Aizenberg’s team developed Slippery Liquid-Infused Porous Surfaces in 2011 and has demonstrated a broad range of applications for the super-slick coating, SLIPS. “Our slippery steel is orders of magnitude more durable than any anti-fouling material that has been developed before,” said Aizenberg. “So far, these 2 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.”
APPS: Non-fouling medical tools and devices, eg implants and scalpels, nozzles for 3D printing and, potentially, larger-scale applications for buildings and marine vessels. The biggest challenge in the development of this surface was to figure out how to structure steel to ensure its anti-fouling capability without mechanical degradation. The team solved this by using an electrochemical technique to grow an ultrathin film of hundreds of thousands of small and rough tungsten-oxide islands directly onto a steel surface.
Mechanical resistance of electrodeposited TO films on stainless steel.
“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. “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.”
“Because we show that this material successfully repels bacteria and blood, small medical implants, tools and surgical instruments like scalpels and needles that require both significant mechanical strength and anti-fouling property are high value-added products we are exploring for application and commercialization,” said Kim.
Another app is functional 3D printing and microarray devices, especially in printing highly viscous and sticky biological and polymeric materials where friction and contamination are major obstacles.
U.S. Navy spends tens of millions of dollars each year dealing with the ramifications of biofouling on hulls. Organisms eg barnacles and algae create drag and increased energy expenditure and costs of cleaning and reapplying current anti-fouling paints. If scaled-up, this material could provide a cleaner, more cost-efficient alternative. http://www.nature.com/ncomms/2015/151020/ncomms9649/full/ncomms9649.html http://www.alphagalileo.org/ViewItem.aspx?ItemId=157444&CultureCode=en
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