Progress made by materials scientists in recent years has greatly helped the field of ultra-precision manufacturing. Ranging from healthcare to electronics components, phenomena such as twinning, dislocation nucleation, and high-pressure phase transformation have helped to exploit plasticity across a wide range of metallic and semiconductor materials. One current problem at the forefront of the healthcare sector that can benefit from these advances is that of bacterial infections in implanted prosthetic devices. The treatment of implant infections is often complicated by the growth of bacterial biofilms on implant surfaces, which form a barrier that effectively protects the infecting organisms from host immune defenses and exogenous antibiotics. Further surgery is usually required to disrupt the biofilm, or to remove the implant altogether to permit antibiotics to clear the infection, incurring considerable cost and healthcare burdens. In this review, we focus on elucidating aspects of bactericidal surfaces inspired by the biological world to inform the design of implant surface treatments that will suppress bacterial colonization. Alongside manufacturing and materials related challenges, the review identifies the most promising natural bactericidal surfaces and provides representative models of their structure, highlighting the importance of the critical slope presented by these surfaces. The scalable production of these complex hierarchical structures on freeform metallic implant surfaces has remained a scientific challenge to date and, as identified by this review, is one of the many 21^st-century puzzles to be addressed by the field of applied physics.

The use of lightweight materials, such as ultra-high-strength aluminium alloys, is in high demand in the automotive and aerospace industries where weight savings are critical. The tool materials used for high-speed cutting of these aluminium alloys are subjected to severe conditions that promote premature failure of cutting tools. The application of polycrystalline diamond (PCD) coatings provides cutting tools with increased mechanical and thermal fatigue resistance and improved tribological performance. Despite these good properties, their high cost remains a major limitation in this sector. Super-hard Diamond-Like Carbon (DLC) coatings offer a technologically and economically feasible alternative to PCD-coated tools for cutting and machining non-ferrous materials. In this paper, the machining performance of coated and un-coated hard metal inserts in the turning of 7075 aluminium alloy has been explored. The surface quality of machined parts, the cutting tool wear resistance and the vibrations generated during turning of un-coated, PCD and super-hard thin DLC coatings on tungsten carbide inserts were compared. The results obtained demonstrate that DLC coatings are a potentially interesting alternative to PCD coatings for machining ultra-high-strength aluminium alloys, where surface component finish is a key factor.

The Boston keratoprosthesis (BKPro) is a critical device for vision restoration in complex cases of corneal blindness, although its long-term retention is challenged by infection risks. This study aims to enhance the antimicrobial properties of the titanium (Ti) backplate of the BKPro by ion implanting silver and copper ions to achieve effective infection control while maintaining cytocompatibility. Research on antimicrobial modifications for BKPro is limited, and while metallic ions like Ag and Cu show promise for biomaterial improvement, their effects on human corneal keratocytes (HCKs) require further study. Ag and Cu were implanted onto rough Ti surfaces, as mono- and coimplantations. Cytotoxicity was assessed in HCKs, and antimicrobial efficacy was tested against Pseudomonas aeruginosa and Candida albicans . After 21 d, monoimplanted Ag samples released 300.4 ppb of Ag ⁺ , coimplanted samples released 427.5 ppb of Ag ⁺ and 272.3 ppb of Cu ions, and monoimplanted Cu samples released 567.0 ppb of Cu ions. All ion-implanted surfaces supported HCK proliferation, exhibited no cytotoxicity, and showed strong antimicrobial activity. Ag-implanted surfaces provided antibacterial effects through membrane disruption and reactive oxygen species generation, while Cu-implanted surfaces exhibited antifungal effects via impaired enzymatic functions and reactive oxygen species. Coimplanted AgCu surfaces demonstrated synergistic antimicrobial effects, resulting from the synergy between the bactericidal actions of Ag and the oxidative stress contributions of Cu. Additionally, ion-implanted surfaces enhanced HCK adhesion under co-culture conditions. In conclusion, ion implantation effectively imparts antimicrobial properties to the Ti backplate of BKPro, reducing infection risks while preserving compatibility with corneal cells.