NOVEL ANTI-MICROBIAL MATERIALS

Anti-microbial coatings and method of forming same on medical devices are provided. The coatings are preferably formed by depositing an anti-microbial, biocompatible metal by vapour deposition techniques to produce atomic disorder i n the coating such that a sustained release of metal ions sufficient to produce an ant i-microbial effect is achieved. Preferred deposition conditions to achieve atomic disorder i nclude a lower than normal substrate temperature, and one or more of a higher than normal working gas pressure and a lower than normal angle of incidence of coating flux. Anti-mi crobial powders formed by vapour deposition or altered by mechanical working to produce atomic disorder are also provided. Novel anti-microbial silver materials are defined, c haracterized by having a positive rest potential, a T rec/Tm less than 0.33, and a grain size less than 200 nm. Anti-microbial fine grain or nanocrystalline materials are provided, togethe r with methods of preparation, wherein the anti-microbial metal if deposited in a matri x with atoms or molecules of a different material such as other biocompatible metals (e x. Ta), trapped or absorbed oxygen, or compounds of anti-microbial metals or biocompatib le metals (ex. Ag0 or TaO).