Bug wings shred bacteria
The bacteria-shredding wings of insects have inspired new antibacterial packaging.
An Australian-Japanese research team says their new, bug-inspired nanotexture kills up to 70 per cent of bacteria and retains its effectiveness when transferred to plastic.
More than 30 per cent of food produced for human consumption is wasted. Sometimes, entire shipments are rejected if bacterial growth is detected.
In an effort to significantly reduce waste, particularly in meat and dairy exports, and to extend the shelf life and improve the quality, safety and integrity of packaged food, researchers have looked to the natural ability of cicadas and other insects.
“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,” says Professor Elena Ivanova of RMIT University.
“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.”
Dragonfly and cicada wings are covered by a vast array of nanopillars – blunted spikes of similar 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.
Bacteria cells were monitored at RMIT’s Microscopy and Microanalysis Facility, with the best antibacterial patterns being shared with a Japan team, who developed a way to reproduce the patterns on plastic polymer.
Back in Australia, Dr Ivanova’s team tested the plastic nanopatterns and found the one which best replicated insect wings but is also easiest to fabricate and scale up.
Dr Ivanova and her colleagues discovered the bacteria killing nature of insect wings a decade ago, and have been working to design the optimal nanopattern to harness insects’ bacteria-killing powers ever since.
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 packaging, among a range of other potential applications, like personal protective equipment.