A laboratory-made nanotexture from an Australian-Japanese team of researchers has been shown to kill up to 70% of bacteria and retain its effectiveness when transferred to plastic. The investigators say that this sets the scene for significantly reducing food waste, particularly in meat and dairy exports, as well as extending the shelf life and improving the quality, safety, and integrity of packaged food on an industrial scale.
Elena Ivanova, PhD, a distinguished professor at RMIT University in Melbourne, Australia, says that her research team successfully applied a natural phenomenon to a synthetic material—plastic. “Eliminating bacterial contamination is a huge step in extending the shelf life of food,” she said in a statement. “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. We have now created a nanotexturing that mimics the bacteria-destroying effect of insect wings and retains its antibacterial power when printed on plastic. This is a big step towards a natural, non-chemical, antibacterial packaging solution for the food and manufacturing industry.”
The research, published in ACS Applied Nano Materials, is a collaboration between RMIT, Tokyo Metropolitan University, and Mitsubishi Chemical’s The KAITEKI Institute.
How It Works
Dragonfly and cicada wings are covered with a vast array of nanopillars, blunted spikes similar in size to bacteria cells. When bacteria settle on a wing, the pattern of nanopillars pulls the cells apart, rupturing their membranes and killing them. “It’s like stretching a latex glove,” Dr. Ivanova said. “As it slowly stretches, the weakest point in the latex will become thinner and eventually tear.”
Dr. Ivanova’s team developed their nanotexture by replicating insects’ nanopillars and developing nanopatterns of their own. The best antibacterial patterns were shared with the Japan team, who developed a way to reproduce the patterns on plastic polymer. Dr. Ivanova’s team then tested the plastic nanopatterns and found the one that best replicated insect wings but was also easiest to fabricate and scale up.
Dr. Ivanova said that dealing with plastic was more difficult than other materials such as silicon and metals due to its flexibility. “The nanotexturing created in this study holds its own when used in rigid plastic. Our next challenge is adapting it for use on softer plastics,” she added.
Since Dr. Ivanova and her colleagues discovered the bacteria killing nature of insect wings a decade ago, they’ve been working to design the optimal nanopattern to harness insects’ bacteria-killing powers and use it on a range of materials. Until recently, it was difficult to find suitable technology to reproduce this nanotexturing on a scale suitable for manufacturing. But now, technology exists to scale up and apply antibacterial properties to food packaging. The team is looking to collaborate with potential partners in the next stage of the research: upscaling the technology and determining the best ways to mass manufacture the product.