The holy grail of natural rubber - an incredibly strong and thin membrane that you can barely feel - could soon improve condoms around the world, thanks to Australian scientists.
A research team at the University of Queensland (UQ) has been working in partnership with local Aboriginal traditional owners to bring the world a unique nanomaterial created out of native spinifex grass (Triodia pungens).
Commercial tests of latex reinforced with spinifex nanocellulose have already shown strong potential for creating super-thin, but strong and durable condoms.
Professor Darren Martin leads the research team at UQ’s Australian Institute for Bioengineering and Nanotechnology (AIBN).
“We tested our latex formulation on a commercial dipping line in the United States and conducted a burst test that inflates condoms and measures the volume and pressure, and on average got a performance increase of 20 per cent in pressure and 40 per cent in volume compared to the commercial latex control sample,” he explained in a press statement.
“With a little more refinement, we think we can engineer a latex condom that’s about 30 per cent thinner, and will still pass all standards,” Martin added. “with more process optimisation work we will be able to make devices even thinner than this.”
The material can also be used for creating thinner latex gloves, improving touch sensitivity for surgeons.
From plant cells to steel-strong membranes
Cellulose is the most abundant natural polymer on our planet, and makes up the cell walls of nearly every green plant, as well as many types of algae. Humans can’t digest it, so we typically refer to it as fiber.
Recent breakthroughs in materials science have allowed researchers to develop nanocellulose, an incredibly strong and flexible material composed of the tiniest cellulose fibres.
“If you compare nanocellulose with hair, it's about 40,000 times smaller. These particles are very small, but strong - almost six times stronger than stainless steel,” said AIBN’s research fellow Dr Nasim Amiralian, who discovered spinifex nanocellulose during her PhD research.
Any cellulose can be turned into nanocellulose, but the most coveted are fibres with a high aspect ratio - meaning they’re long and thin, Amiralian explained. She describes spinifex nanocellulose as unique, because the tiny fibres are the longest and thinnest yet found in any plant.
Indigenous Australians have long used resin from some species of spinifex grass as an adhesive for building tools and weapons.
Dr Amiralian told SBS Science that her original goal was to study potential new applications for this resin, when she had a brainwave.
"It came to me that spinifex would produce nanocellulose, and because of the specific conditions in which this grass grows - a harsh, hot environment - I thought that it probably gives different properties to this grass."
Boosting local jobs and advanced manufacturing
Native spinifex is comprised of 69 different species, which cover nearly 27 percent of Australia’s landmass, and Triodia pungens is the species found in north-west Queensland.
Last year UQ reached an agreement with the local Dugalunji Aboriginal Corporation (DAC) to ensure that local traditional owners would be recognised for their knowledge of spinifex, and have ongoing equity and involvement in the commercialisation of this unique nanocellulose.
Now that the commercial tests have shown great potential for the new spinifex nanocellulose technology, cultivation and processing of the grass will be done locally in the remote areas where it grows.
“We’re very excited by the prospects of commercialising the technology to provide an entirely new industry to regional Australia,” said DAC managing director Colin Saltmere.
“This project will develop Australia's advanced manufacturing,” added Dr Amiralian. “It will also provide job opportunities for Indigenous people in rural Queensland, by developing production plants for harvesting and primary processing of spinifex nanocellulose.”
The researchers believe their technology will attract latex product manufacturers in the global market, because spinifex nanocellulose is also easy and relatively cheap to extract. In addition, a super-strong and thin, satisfying condom would use less latex overall, driving the costs down further.
The team at UQ haven’t yet published a study describing their new latex formulation, but a patent application is currently in place, said Dr Amiralian.