The interest in antimicrobial solutions for touch screens has increased in recent years, as traditional methods like alcohol sprays and wipes are not ideal for delicate displays. Antimicrobial coatings applied directly to the glass have shown promise, but previous solutions have posed challenges and required light and moisture. Copper is a well-known biocidal metal, but its opaque nature and high conductivity have made it unsuitable for transparent applications on displays.
A team of researchers has developed a transparent nanostructured copper surface (TANCS) that is non-conductive and resistant to certain bacteria. The fabrication process involves depositing a thin copper film onto a glass substrate and using a thermal annealing process to create dewetted copper nanoparticles. Additional layers of SiO2 and fluorosilanes are then added for environmental protection and improved durability. The TANCS has shown an antimicrobial effect, transparency, color neutrality, and electrical insulation in testing.
The authors of the study examined the coating’s morphology, optical response, antimicrobial efficacy, and mechanical durability. The TANCS was able to eliminate over 99.9% of “Staphylococcus Aureus” within two hours under dry test conditions. It also showed optical transparency, with 70-80% light transmission in the visible range, and demonstrated prolonged antimicrobial effectiveness even after rigorous wipe testing. The researchers believe that the dewetting process opens up new possibilities for exploiting specific properties of metals while maintaining transparency and insulation.
The introduction of transparent antimicrobial surfaces holds promise for touchable displays like smartphones and tablets. While further development is needed for commercial deployment, the researchers see this as a step towards enabling antimicrobial touch screens for public and personal use. The collaborative effort between ICFO researchers and Corning has resulted in a proof-of-concept surface that showcases the potential of nanostructuring in developing advanced glass screens for improved display of information and information security. The research has been partially funded by the Nano-Glass project, which aims to develop innovative nanostructuring designs and methods for glass screens and optical fibers.
