Comparative Analysis of Time-Dependent Antibacterial and Antiviral Properties of Cold-Sprayed Copper Coatings vs. Bulk Copper

This study builds on previous research into the potential of cold-sprayed copper coatings as self-disinfecting surfaces to reduce fomite transmission on frequently touched surfaces in public spaces. We investigate the time-dependent antimicrobial efficacy of copper powder and the resulting cold-sprayed coatings compared to bulk copper against different bacteria, including Staphylococcus aureus and Pseudomonas aeruginosa, and viruses, including VSV-G, hCoV 229E, and VSV. Under various experimental conditions, our results demonstrate complete inactivation within 10 to 90 minutes of contact, with cold-sprayed copper coatings exhibiting faster inactivation rates than bulk copper, particularly for bacterial elimination. Accelerated aging tests were conducted to evaluate the durability of these coatings simulating regular contact and cleaning procedures in public settings. However, the results revealed limited long-term viability of pure copper for high-touch surfaces. Preliminary results suggest copper alloys with high corrosion and wear resistance could offer antimicrobial performance comparable to pure copper, making them potentially more suitable for this application.