Researchers at RMIT University have created a thin plastic film covered in nanoscale pillars that physically destroys viruses on contact, offering a chemical-free alternative to conventional disinfectants.
The film’s surface mimics the nanotextured wings of insects like cicadas and dragonflies, using precisely spaced nanopillars to stretch and rupture viral membranes through mechanical force alone. In laboratory tests, this approach inactivated about 94% of human parainfluenza virus type 3 (hPIV-3) particles within one hour, damaging them to the point they could no longer replicate or cause infection.
Unlike chemical disinfectants that require dwell time, can degrade surfaces, and contribute to antimicrobial resistance, this antiviral film works instantly and leaves no residue. It also avoids the health and environmental risks associated with earlier antiviral coatings that relied on metals or natural agents prone to leaching or loss of potency over time.
The breakthrough stems from more than a decade of research that began with an attempt to create germ-repelling surfaces — only to discover that extreme smoothness actually helps bacteria adhere. Studying insect wings revealed that their bactericidal effect comes not from chemistry but from topography: nanoscale structures that puncture or stretch microbial membranes.
Nanopillar spacing determines antiviral effectiveness more than height
The RMIT team found that the distance between nanopillars is far more critical to viral rupture than their height. Optimal performance occurs when pillars are spaced about 60 nanometres apart, allowing multiple points of contact to simultaneously stretch a virus’s lipid envelope beyond its breaking point.
When spacing exceeds 100 nanometres, the antiviral effect drops sharply, and at around 200 nanometres, the surface loses virtually all virucidal activity. This insight shifts the design focus from feature height to precise nanoscale patterning, which could guide future development of antimicrobial surfaces.
Scalable manufacturing could enable widespread use on high-touch surfaces
The film is made from flexible acrylic that can be produced in continuous rolls using existing roll-to-roll fabrication techniques, the same method used to make plastic wrap. This compatibility with industrial-scale processes means the material could be manufactured cheaply and at volume without requiring new factory equipment.
Potential applications include smartphones, keyboards, hospital tables, and other frequently touched surfaces where viral transmission poses a risk. The lead author, PhD candidate Samson Mah, noted that the mould for the film could be adapted for high-throughput production, bringing lab-scale success closer to real-world deployment.
Current tests limited to one virus type; broader efficacy and real-world durability remain unproven
So far, the film has only been tested against hPIV-3, an enveloped virus with a fatty outer membrane. Researchers acknowledge they must now evaluate whether the same mechanical principle works on smaller or non-enveloped viruses, which may have different structural vulnerabilities.
studies are needed to assess how well the nanotextured surface performs on curved or irregular objects, and whether its antiviral properties hold up under repeated use, cleaning, or environmental exposure. The technology remains in the laboratory phase, with no timeline announced for commercial availability.
How does this film kill viruses without using chemicals?
The film’s surface is covered in tiny nanopillars that latch onto a virus’s outer envelope and stretch it mechanically until it ruptures, inactivating the virus through physical force rather than chemical disinfection.
Why is the spacing between nanopillars more crucial than their height?
At approximately 60 nanometres apart, multiple nanopillars can grip a single virus particle simultaneously, stretching its membrane beyond its physical limits; wider spacing reduces this effect, rendering the surface ineffective at around 200 nanometres.
Can this film be used on everyday objects like phones or hospital equipment?
Yes, the film is made from flexible acrylic that can be manufactured in rolls using existing industrial equipment, making it suitable for application on high-touch surfaces such as smartphones, keyboards, and medical devices — though real-world durability testing is still needed.
