Effects of critical design parameters on antibacterial efficacy of a silver ions-based antibacterial surface system

Infections are frequently transmitted in healthcare environments via fomite surfaces such as door push plates, countertops, and surgical instruments. Lower immunity of patients coupled with the emergence of antibiotic-resistant bacteria such as methicillin-resistant Staphylococcus aureus (MRSA) makes the problem of the spread of such infections even more critical. We have developed an inherently antibacterial surface system that utilizes electrically activated silver ions to prevent indirect contact transmission of pathogens. The surface consists of a grating pattern of alternate silver electrodes and polymer partitions activated by direct electric current in the order of a few microamperes. In this paper, we present the effects of the two most critical design parameters, size of features and magnitude of electric current, on antibacterial efficacy of the surface system against E. coli. The results show that smaller feature widths and higher electric current lead to a more effective antibacterial surface. The implications of these results on the costs and practical applications of the antibacterial surface system are also discussed.