Lithography-free fabrication of transparent, durable surfaces with embedded functional materials in glass nanoholes

Iliyan Karadzhov, Rubaiya Hussain, Alessia Mezzadrelli, Wageesha Senaratne, Prantik Mazumder, Valerio Pruneri; Lithography-free fabrication of transparent, durable surfaces with embedded functional materials in glass nanoholes. APL Mater. 1 December 2025; 13 (12): 121112. https://doi.org/10.1063/5.0304861

Abstract

Touch-enabled technologies, from smartphones to public kiosks, are ubiquitous, yet frequent use turns their surfaces into reservoirs for microbial contamination. Routine alcohol-based cleaning can be impractical on high-touch optical surfaces due to damage risk and usability concerns. Here, we present a scalable approach to transparent, mechanically robust glass surfaces by embedding materials with ad hoc functionality into surface glass nanoholes. We demonstrate the concept with copper nanodisks: copper is an established antimicrobial agent, but its wear susceptibility pose challenges for use on transparent displays. Our design shields the functional material from lateral wear while allowing ion diffusion for antimicrobial efficacy. Fabrication uses only wafer-compatible, lithography-free steps: thermal dewetting of a thin silver film to create a nanosized mask; inverting it to a polymer nanoholes mask by etching the silver nanoparticles; wet etching of the glass to form nanoholes; selective copper deposition inside these holes; and liftoff of excess material. The resulting surfaces exhibit mean transmission of 80%–85% in the 380–750 nm range with haze and minimal color shift, compared to uncoated glass. Antimicrobial efficacy, assessed against Escherichia coli OP50 under a modified U.S. EPA protocol, shows ≈99% bacterial reduction within one hour. Abrasion tests with a crockmeter simulating finger swipes confirm that the embedded copper remains intact, with no measurable change in optical performance. This embedded design provides a scalable route to integrate antimicrobial functionality into high-touch transparent systems while preserving optical clarity and wear resistance, with potential relevance for medical, consumer, and transportation interfaces.

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