Textiles, when exposed to light, release a burst of energy that degrades organic matter.

Scientists are flushed with success: sunshine to replace the need to wash clothes, while toilets will no longer need water

Developments in nanotechnology are leading to applications such as wash-free garments, waterless toilets, and new types of medicine

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John Lam

Published: 9:48am, 1 Aug 2016

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Could clothing that never needs washing really help save the world?

That may seem a stretch, given all the genuine problems the planet and humankind are facing. But you have to start somewhere, and the men and women in lab coats beavering away at nanotechnology seem to think that it’s as good a place as any.

In a nutshell, nanotechnology refers to the study and application of really small things. If you’re wondering what this has to do with you, a cursory glance at www.dummies.com suggests nanotechnology has the capacity to change life as we know it – to “increase your standard of living; make our lives more secure; improve health care delivery; and optimise our use of limited resources”.

The site notes that mankind “has spent millennia trying to fill these needs”, which it cites as the basics for ensuring our future. If nanotechnological applications pan out in the direction they are headed, it asserts, “we are one step closer to ensuring that future”.

Think of materials 10 times stronger than steel, at a fraction of the weight; and smaller and more powerful computers encrypting our data for safekeeping. But here’s the thing: nanotechnology could also hold the key to sustainable use of global resources, such as energy and water. With one in 10 people globally lacking access to safe drinking water, and one in three without proper sanitation, according to www.water.org/water-crisis, wash-free garments begin to make sense – as do waterless toilets, another area of nanotechnology research.

Self-cleaning textiles are being explored at RMIT University in Melbourne, Australia. In this pioneering technology, researchers have been growing nanostructures on cotton fabric which, when exposed to light, release a burst of energy that then degrades organic matter. So a little ray or sunshine – or even a light bulb – could, in effect, clean your clothes for you.

As the scientists explain it, the nanostructure is metal-based, so it can absorb visible light. This creates energy, which is able to degrade organic matter on which it is present [the textile], “so that's how it'll get rid of stains".

Tests on stains have proven promising, say the scientists, with results achieved within between six and 30 minutes of light exposure, depending on the material. The research is now moving on to sweat testing.

Dropel says its stain-resistant fabrics look and feel like regular textiles.

Stain-free fabrics have been around for a while, but they haven’t felt as comfortable as traditional textiles. Dropel Fabrics, a creator of hydrophobic natural textiles, is working to overcome that. It has developed a patented nanotechnology process infuses cotton fibres with water, stain, and odour repellent properties, while maintaining, the company says, the textile’s softness and breathability.

Technology is making garments resistant even to spills like red wine and tomato sauce.

Apparently, it involves a “simple process” which encapsulates polymers within the textile fibres, and creates a protective layer. Invisible to the hand and eye, this protective layer does not affect the fabric’s texture, so its softness and construction is maintained. The company says it is exploring partnerships with high-end fashion brands.

The waterless Nano Membrane Toilet, developed by scientists at the UK’s Cranfield University.

Meanwhile, scientists at Britain’s Cranfield University are developing a toilet which does not need water, a sewage system or external power, but instead uses nanotechnology to treat human waste. The innovative Nano Membrane Toilet uses a rotating mechanism to move waste into a holding chamber containing nano elements. The mechanism also blocks odours, and conceals from view the human waste, which is then converted to water and ash. (See https://www.youtube.com/watch?v=iX0jAn-iNng.) The research, funded by the Bill & Melinda Gates Foundation, aims to enable those without plumbing to have access to safe and hygienic facilities.

Mexican designers’ concept for a waterless toilet for an urban apartment.

Two Mexican industrial designers are working on their own solution for a waterless toilet, this time designed for urban areas. Reasoning that even some apartment dwellers have no access to sewage, their concept turns human waste into greywater which can safely be disposed of down the household drain.

Nanotechnology also has huge potential in the medical field – in particular for fighting global epidemics of viruses such as zika and ebola. Recently, IBM Research and Singapore's Institute of Bioengineering and Nanotechnology identified a breakthrough macromolecule that could help prevent deadly virus infections, and also help prevent viral drug resistance.

According to Dr Yi Yan Yang, group leader, Institute of Bioengineering and Nanotechnology, Singapore, this breakthrough – resulting from work in the field and collaboration with researchers globally – could lead to the development of a new mode of vaccination which could help prevent a whole category of viral infections, a leading cause of morbidity and mortality. The short-term potential could be for applications such as an antiviral wipe or detergent, she adds.

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