Controlling bacteria retention on polymer via replication of laser micro/nano textured metal mould

Abstract

Polymer materials including paints and objects are widely used in our daily life. Keeping them free from bacteria without the use of any antibacterial agents is of high interest to the public. In this paper, we demonstrate a method for significantly reducing bacteria adhesion and growth on a polymer surfaces by generating a specific surface micro/nano structure. A metallic template was prepared using laser micro/nano surface texturing on Ti6Al4V surfaces. Then the negative surface structure was transferred onto a polydimethylsiloxane (PDMS) polymer using soft lithography. Staphylococcus aureus (S. aureus) retention assays were used to determine the number of retained bacteria on the replicated polymer surfaces. Results showed that on all the replicated plastic surfaces, the number of adhesive bacteria was much reduced (up to a fivefold reduction) compared to that on the non-textured polymer surfaces. This was largely due to the reduced wettability with a water contact angle close to 150° on the replicated polymer surface that contained specific micro/nano structures. This finding could lead to potentially applications for reducing bacteria adhesion or fouling on painted surfaces (e.g. ship hulls) and plastic objects (e.g. phones and computer keyboards) using nanostructure transfer from metal templates by, for example, stamping and hot/cold embossing and injection moulding.