A tough, spiky grass might not sound like a good ingredient for condoms, but it could be the secret to making them thinner and more reliable.
Fibres from the Australian grass spinifex are being used to make condoms that could be as thin as a human hair without any loss in strength, researchers said.
Nanocellulose is a material extracted from plant fibres, and often used to strengthen polymers like latex. Nasim Amiralian from the University of Queensland discovered that those extracted from spinifex were unique. The microscopic fibres were longer, thinner, stronger and more flexible than any others she’d seen.
“Because of all those properties ... when we add the nanocellulose to a latex membrane, we could produce a very thin membrane which is stronger,” Amiralian told Guardian Australia. “So it still gives you a better sensation, but it is reliable and safe.”
And tests of the new additive have been successful so far, Darren Martin from the University of Queensland said. “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% in pressure and 40% in volume compared to the commercial latex control sample,” he said.
“With a little more refinement, we think we can engineer a latex condom that’s about 30% thinner, and will still pass all standards, and with more process optimisation work we will be able to make devices even thinner than this.”
The researchers said they were working with Aboriginal traditional owners of the Camooweal region in north-west Queensland, the Indjalandji-Dhidhanu People to recognise their knowledge about spinifex and to ensure they had involvement in the project.
Martin said spinifex had long been used as an effective adhesive by Indigenous communities in Australia. “Spinifex resins have been used traditionally for attaching spear heads to their wooden shafts,” he said.
Making stronger polymers wasn’t just about making more comfortable condoms, Amiralian said. It could also be used for better surgical gloves and for medical devices like the balloons used to inflate arteries and other blood vessels.
The researchers said they had expressions of interest from condom and medical device manufacturers and were looking to commercialise the product.
