Methodological issues in evaluating the antimicrobial efficiency of antimicrobial-superhydrophobic fabrics

Antimicrobial textiles are desired in areas such as sportswear, inner garments, and upholstery. Recently, dual functional (antimicrobial and superhydrophobic) fabrics are proposed to mitigate the threat of hospital-acquired infections (HAIs). Numerous studies suggest the risk of hospital textiles causing cross-contamination; because HAI-related pathogens can survive on hospital textiles (such as doctor/nurse uniform, patient bedding, linen) due to contact with infected patients and the contaminated fluids (urine, vomit, sneeze etc.). In such scenario, antimicrobial functionality can kill the adhered bacteria while a superhydrophobic surface can repel pathogen-rich fluids splashes and droplets. Due to the non-wetting property of the dual functional fabrics, their antimicrobial performance evaluation by conventional tests is challenging as absorption of bacterial culture is a prime need for such tests. The superhydrophobic nature inhibits adhesion of bacteria to the fabric surface. Therefore, in this work, we have initiated certain changes in the protocol of the AATCC 100:2012 test method to realize consistent and reliable evaluation of the antimicrobial performance of dual functional fabrics. The new test method is likely to facilitate the adoption of dual functional fabrics in practical applications.