Researchers at the University of Birmingham in the UK have developed a new type of stainless steel that is more durable and resists bacteria. Led by professor of surface engineering Hanshan Dong, the researchers melded copper or silver into the surface of the steel to make a hybrid metal, rather than using the two metals to coat the surface of the steel. To do so, the researchers had to develop a new surface alloying technology, which they did using Active Screen Plasma (ASP).
The ASP process introduces silver, along with nitrogen and carbon, into the steel. Silver is an antibacterial agent, and the nitrogen and carbon increase the steel’s strength and durability. The end result is stainless steel that could be more effective when used in everyday applications, like in the kitchen, or in situations where cleanliness is critical, like medical instruments.
In a University of Birmingham press release, Dong says:
“Previous attempts to make stainless steel resistant to bacteria have not been successful as these have involved coatings which are too soft and not hard-wearing. Thin antibacterial coatings can be easily worn down when interacting with other surfaces, which leads to a low durability of the antibacterial surface. Our technique means that we avoid coating the surface, instead we modify the top layers of the surface.”
The researchers tested their hybrid metal material as medical instruments, and found that even after 120 cleanings, the stainless steel retained its antibacterial abilities and showed no signs of wear.