A team of researchers from RMIT University in Melbourne, Australia, Tokyo Metropolitan University, and Mitsubishi Chemical’s The KAITEKI Institute have created an antibacterial nanotexture for rigid plastic packaging.
The material is inspired by the wings of dragonflies and cicadas which are covered in nanopillars of similar size to bacterial cells. These can kill bacteria by pulling, stretching, or slicing them apart. When bacteria settle on the wing, the pattern of the nanopillars pulls the cells apart, in turn rupturing their membranes and killing them.
Distinguished Professor Elena Ivanova’s team at RMIT University, the Mechano-bactericidal Materials Research Group, developed a nanotexture that replicated the insects’ nanopillars, thus creating nanopatterns of their own. The antibacterial properties of these nanopatterns were then monitored at RMIT’s Microscopy and Microanalysis Facility.
The team in Japan developed a way to reproduce the patterns on plastic polymers. These were later tested by the Australian team in order to identify the one that best replicated insect wings while being easiest to fabricate and scale up.
According to the research team, the nanotexture developed in the laboratory can eliminate 70% of bacteria. The team suggests that the nanotexture could be used in packaging to reduce waste both during exports, as entire shipments can be rejected if bacterial growth is detected, and while on the shelf.
Ivanova adds: “Eliminating bacterial contamination is a huge step in extending the shelf life of food. (…) “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.”
Ivanova and her colleagues discovered the bacteria-killing nature of insect wings a decade ago, but lacked the proper technology to reproduce this nanotexture on an appropriate scale for manufacturing until now. The research group says that the antibacterial nanotexture can be applied to packaging, along with other potential applications, such as personal protective equipment.
Ivanova added: “The nanotexturing created in this study holds its own when used in rigid plastic. Our next challenge is adapting it for use on softer plastic.”
The team hopes to collaborate with potential partners in the next stage of the research, which will involve upscaling the technology and determining the best ways to mass manufacture the antibacterial packaging.
The research was supported by the Foundation for Australia-Japan Studies under the Rio Tinto Australia-Japan Collaboration Project. Ivanova’s co-authors include Denver Linklater, Soichiro Saita, Takaaki Murata, Chaitali Dekiwadia, Russell Crawford, Hideki Masuda, and Haruhiko Kusaka.
