Nanopillar-Studded Plastic Films Physically Destroy Viruses, Cutting Infectivity by 94% without Chemicals

Key Takeaways

• 60 nm pitch nanopillars cut viral infectivity 94% in 1 h
• UV nano‑imprint lithography enables roll‑to‑roll scalable production
• Mechanical stress, not chemistry, ruptures viral envelopes
• Effectiveness driven by pillar spacing, not height
• Flexible, transparent films suit medical and consumer surfaces

Summary

Researchers at RMIT and international partners engineered flexible acrylic films stamped with dense nanopillar arrays using ultraviolet nano‑imprint lithography. The 60 nm pitch configuration reduced human parainfluenza virus type 3 infectivity by up to 94 % within one hour, achieving mechanical rupture of viral envelopes without any chemical additives. The process is compatible with roll‑to‑roll manufacturing, yielding transparent, bendable films suitable for large‑scale deployment. This mechano‑virucidal approach offers a durable, chemical‑free alternative to traditional disinfectant coatings.

Pulse Analysis

The search for surface‑based infection control has long been dominated by chemical agents—silver, copper, or biocidal polymers—whose efficacy wanes as they leach or degrade. Nature offers a different blueprint: the nanospike‑covered wings of cicadas and dragonflies physically destroy microbes. Translating this mechano‑bactericidal principle to viruses required nanostructures far smaller than bacterial spikes, prompting researchers to explore polymeric nanopillars that can engage viral envelopes at the nanoscale.

In the recent Advanced Science study, a multinational team fabricated acrylic films with precisely spaced nanopillars ranging from 60 nm to 200 nm pitch. Using ultraviolet nano‑imprint lithography, they stamped ordered arrays onto a photocurable resin, a method already suited to continuous roll‑to‑roll production. Testing against hPIV‑3 revealed that the densest 60 nm pitch surfaces achieved a 0.7‑log average reduction, peaking at a 1.2‑log (≈94 %) drop after one hour. Electron microscopy showed viral particles deformed and ruptured between multiple pillars, confirming that tensile stress—not chemical attack—neutralized infectivity, and that pillar spacing, rather than height, governed performance.

The implications extend beyond a single virus. Because the antiviral mechanism relies on geometry, the design rule of a pillar‑to‑virus diameter ratio of 0.2‑0.5 can be adapted to other enveloped pathogens. The films are transparent, flexible, and chemically inert, making them ideal for high‑touch surfaces in hospitals, consumer electronics, and food packaging. Their chemical‑free nature sidesteps toxicity concerns and eliminates the risk of resistance development, while the roll‑to‑roll process promises cost‑effective, mass‑market adoption. As industries seek sustainable, long‑lasting disinfection solutions, mechano‑virucidal nanopillar films could become a new standard for passive pathogen control.