Flexible Plastic Film Uses Nanostructures to Destroy Viruses

Human parainfluenza virus 3 (hPIV-3), which can cause bronchiolitis and pneumonia, persists on plastics commonly found on devices and equipment. Frequent chemical cleaning is labor intensive and can damage materials. To help address this challenge, researchers have developed a nanotextured plastic film that mechanically destroys viruses on contact.

Developed at RMIT University (Melbourne, Australia), the innovation is a thin, flexible acrylic film patterned with ultra‑fine nanopillars. The surface is designed for practical deployment on smartphones, keyboards, touch screens, and hospital equipment. It uses mechanical forces rather than chemicals, offering a route to continuous antiviral activity between standard cleaning cycles.

The nanopillars grab and stretch the viral outer shell until it ruptures, inactivating the particle. Research published in Advanced Science reports that stretching was more effective than the “skewering” approach described for earlier metal or silicon surfaces. In laboratory tests against human parainfluenza virus 3, about 94% of particles were torn apart or damaged so they could no longer replicate within one hour of contact.

Design studies showed that nanopillar spacing was more important than height for antiviral performance. Densely packed features with approximately 60 nanometers between pillars delivered the strongest effect, wider 100‑nanometer gaps reduced activity, and 200‑nanometer spacing effectively eliminated it. The team fabricated the film from inexpensive, roll‑processable acrylic, indicating compatibility with large‑scale manufacturing. The findings also confirm efficient mechano‑virucidal action on flexible plastics, not only on rigid nanospike substrates.

The researchers note that enveloped viruses, which have a fragile fatty membrane, may be more readily disrupted by the nanopillars than non‑enveloped viruses. Planned work includes testing against smaller and non‑enveloped viruses and evaluating performance on curved surfaces where spacing geometry changes. The study, “Designing Scalable Mechano‑Virucidal Nanostructured Acrylic Surfaces for Enhanced Viral Inactivation,” was published in Advanced Science.

“As nanofabrication tools get better, our results give a clearer guide to which nanopatterns work best to kill viruses,” said Samson Mah, PhD candidate, RMIT University. "We could one day have surfaces like phone screens, keyboards and hospital tables covered with this film, killing viruses on contact without using harsh chemicals. Our mould can be adapted to roll‑to‑roll manufacturing, meaning antiviral plastic films could be produced at scale with existing factory equipment."

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