Diamond-like carbon coating of alternative metal alloys for medical and surgical applications

The effectiveness of a plasma-deposited, diamond-like carbon (DLC) coating on aluminium alloy based surgical instruments is investigated. Surgical instruments must satisfy a number of important criteria including biocompatibility, functional performance, sterility and cleanability, structural integrity, and fatigue resistance. The integrity of the DLC layer and the diffusion barrier properties are of paramount importance due to biocompatibility considerations of the underlying aluminium metal. We investigate the optimisation of the coating with incorporation of silicon and variation in negative self bias, and highlight the design and manufacture of a lightweight laparoscopic assist instrument from aluminium alloy coated with diamond-like carbon, which has been used successfully in the clinical environment to improve operations such as cholecystectomy (gall bladder removal) and exploratory techniques for the diagnosis of cancer.