Scientists, drawing insight from the ability of certain insects’ wings to kill bacteria, have created food packaging that significantly improves shelf life and cuts waste, according to a new study that appeared in ACS Applied Nano Materials.
The research team created the natural antibacterial texture by applying a natural occurrence observed in the wings of some insects, including cicadas and dragonflies. This new material can kill as much as 70 percent of bacteria, scientists said.
The study involved researchers from the Royal Melbourne Institute of Technology (RMIT), Tokyo Metropolitan University, and The KAITEKI Institute of Mitsubishi Chemical.
“We knew the wings of cicadas and dragonflies were highly efficient bacteria killers and could help inspire a solution, but replicating nature is always a challenge,” said RMIT University’s Distinguished Professor Elena Ivanova. “We have now created a nanotexturing that mimics the bacteria-destroying effect of insect wings and retains its antibacterial power when printed on plastic.”
Bacteria causes wastage of a significant proportion of food intended for human consumption each year – estimated at over 30 percent. They are especially a problem with dairy and meat products. Any bacteria growth can cause an entire shipment to be rejected.
The novel food packaging will hopefully help to combat wastage and extend the shelf life of food products.
There are numerous nanopillars on the wings of cicadas and dragonflies. These blunted structures are about the same size as bacteria cells. They bond with bacterial membranes and pull the cells apart, thus rupturing and killing them.
Ivanova compared the pulling apart of bacteria cells to the stretching of a latex glove. The weakest point becomes thinner as the latex is slowly stretched until it tears.
It has been 10 years since Ivanova’s team first observed the ability of insect wings to destroy bacterial cells in this way.
The researchers have been working all this time to create patterns that can replicate the ability of insect wings’ nanopillars to kill bacteria cells. But it had proved difficult to pull this off on a large scale due to a lack of the right technology.
Things have changed. Technology exists now to make the scaling up of nanotexture production possible.
Novel antibacterial packaging
Research published two years ago showed how nanomaterials inspired by insect wings can be used to tackle resistant bacteria. This new study builds on that work.
Ivanova and her fellow researchers assessed the ability of their nanopatterns to destroy bacteria cells at the Microscopy and Microanalysis Facility at RMIT with state-of-the-art equipment. They were looking to identify not just the patterns with powers similar to insect wings but that were also easiest to make and scale up.
The team in Australia then shared what it considered to be the best patterns with the one in Japan. The latter was in charge of finding a means of reproducing the nanopatterns on plastic polymer.
Ivanova noted that flexibility made working with plastic harder than with other materials, such as metals and silicon.
“The nanotexturing created in this study holds its own when used in rigid plastic,” she said. “Our next challenge is adapting it for use on softer plastics.”
The research team is now looking forward to working with interested partners to upscale the technology. It plans to find the best means of mass producing the natural antibacterial packaging solution.
Packaging is only one of the possible uses of the new antibacterial nanotexturing. Researchers said that it can also be used for personal protective equipment, among others.