A spikey, prickly grass found in the Australian outback is being farmed commercially to manufacture condoms that are strong but as thin as the human hair. Researchers from the University of Queensland have developed a way of extracting nanocellulose from the grass and using it as an additive in latex production.
"We're getting a 20 per cent increase in the burst pressure, the strength, and we're getting a 40 per cent increase in the burst volume," said Professor Darren Martin from UQ. "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, and with more process optimisation work we will be able to make devices even thinner than this."
The spinifex grass contains long fibres that can make plastics and rubbers more durable. This could also help manufacture thin, strong gloves that give a sensitive feel when used by surgeons.
The natives have been using the grass for thousands of years as an effective adhesive to make spears, chisels and knives, the professor told ABC News. The pilot plant being commissioned can make five kgs of condoms a day, so "during the year we could make enough nanocellulose to go into every condom on the planet".
The harvested grass is thrashed and broken down. In lab it is then ground into a powder and pulped to give nanofibres. High pressure is used to peel the nano-fibres apart from the pulp and become nanocellulose suspended in water and ready to add to things like water-based rubber latex, said UQ's Australian Institute for Bioengineering and Nanotechnology (AIBN) Dr Nasim Amiralian.
Spinifex grass is found in nearly 30 per cent of outback Australia. The project is being used to help train Indigenous rangers. UQ and the Dugalunji Aboriginal Corporation have signed an agreement to recognise local Aboriginal traditional owners' knowledge about spinifex and to ensure they profit from the commercialisation of the grass technology.