Mechano-Bactericidal Based Transparent Antimicrobial Surfaces via Inverted Glancing Angle Deposition (I-GLAD)

This paper presents the nanofabrication of transparent, mechano-bactericidal surfaces using Inverted Glancing Angle Deposition (I-GLAD). Inspired by natural antimicrobial mechanisms, the fabricated surfaces feature needle-like nanostructures that physically rupture microbial cells upon contact, thereby offering a passive method of microbial elimination and reducing the risk of antimicrobial resistance (AMR). Despite their promise, replicating such mechano-bactericidal surfaces artificially—particularly on transparent materials—remains challenging due to the complexity of the required three-dimensional nanostructures. Leveraging the I-GLAD technique, an advanced form of physical vapor deposition, this study successfully fabricates large-area surfaces with nanoneedles featuring sub-10 nm tip sizes. The manuscript explores the critical process parameters for inversion, emphasizing the necessity of a deposition incident angle exceeding 79°, as validated through tape adhesion testing. Additionally, the integration of transparent materials into the I-GLAD process enables the creation of optically clear antimicrobial films. Optical transmittance and bacterial viability tests confirm the dual functionality of these surfaces. The transparent I-GLAD antimicrobial coatings hold significant potential for applications in healthcare, consumer electronics, and other daily-use environments requiring both visibility and sterility.