Micropatterned CuS@PDMS films with anti-adhesive property for photothermal sterilization

This study presents the development of micropatterned polydimethylsiloxane (PDMS) films with hollow CuS NPs (p-CuS@PDMS) designed for both anti-adhesive and photothermal sterilization applications. Hollow CuS nanoparticles (NPs) synthesized via the Kirkendall effect were incorporated into PDMS films to enhance the photothermal conversion. Micropatterning, achieved through a yogurt lid templating method, increased surface roughness and hydrophobicity and significantly reduced bacterial adhesion. The improved anti-adhesive properties were demonstrated by water contact angle measurements, which showed an increase of 24° from 103° to 127° for the micropatterned p-CuS@PDMS films. Under near-infrared (NIR) irradiation, the p-CuS@PDMS films achieved a temperature increase of 91 °C with a photothermal conversion efficiency of 73 %, which is much higher than the 61 °C achieved by plain PDMS. The presence of CuS NPs in the PDMS matrix improved the bacterial inactivation rates, with p-CuS@PDMS achieving a 99 % bacterial kill rate after 90 s of irradiation. Although the anti-adhesive properties were influenced more by micropatterning, the combination of CuS and micropatterning provided a synergistic effect. These results demonstrate the potential of p-CuS@PDMS films for applications in healthcare and packaging, where effective sterilization and bacterial resistance are critical.