Evaluation of antimicrobial abilities of Cr2N/Cu multilayered thin films

Nine kinds of nanostructured Cr2N/Cu multilayer thin films were deposited by the bipolar asymmetry reactive pulsed DC magnetron sputtering system. The antibacterial tests of coatings with various bilayer periods (Λ) and different Cr2N/Cu thickness ratios were performed to evaluate the bactericidal ability by E. coli, S. aureus and P. aeruginosa, respectively. The Λ value, thickness values of Cr2N to Cu layers significantly affected the bactericidal rates. The 100% bactericidal rates were achieved when the Λ value reached 20 nm. For the same Λ = 12 nm Cr2N/Cu multilayered coatings, the thickness ratio of Cr2N to Cu also showed strong influence on the bactericidal rates.