The transmission chain of Health-care Associated Infections (HAI), which involves frequently-touched surfaces, makes the development of anticontamination strategies crucial to reduce HAI risk. Cu-based alloys have attracted considerable interest as anticontamination materials since they can rapidly inactivate bacteria, yeasts, viruses and multi-drug resistant pathogens more effectively than stainless steel and polymers. Therefore, Cu-based materials will be essential to reduce the infection risk from high-touch surfaces in the following years. Critical information about Cu-based materials microstructure and micromechanical properties should be considered when evaluating antimicrobial capability. These features become especially relevant when applying thin rolled foils on pre-existing surfaces as a simple and cost-effective anticontamination method.

This work aims at developing Cu-based thin-rolled foils with a suitable trade-off between workability, mechanical and antimicrobial properties by optimising alloy composition. Hence, Cu15Zn and Cu18Ni20Zn with foil thicknesses ranging from 15 to 25 μm were investigated against PHC Cu (99.95 wt.%) used as the benchmark.

Microstructural characterisation was carried out by Optical and Electronic Scanning Microscopy. Mechanical properties of thin Cu-based foils were tested with a view to the thin foil thickness involved: for this purpose, room-temperature nanoindentation and miniaturised membrane bulge tests combined with digital image correlation were used. Subsequently, the Cu-based foils were exposed to SARS-CoV-2 for different time points, evaluating their antiviral capability. The results highlighted that all the investigated Cu-based alloys completely inactivated SARS-CoV-2 in max. 10 minutes (with the lowest inactivation time of 2 minutes measured for Cu PHC rolled without final recrystallization annealing), while Cu15Zn presented the most promising trade-off between micromechanical performance and antiviral properties.