Water-borne diseases kill millions of people every year. The flow-on effects of poor sanitation and lack of access to safe drinking water can impact almost every aspect of life, from preventing children from attending school to exposing women to sexual violence when they go to collect water from distant sources. The World Health Organisation estimates that 4% of the global disease burden could be prevented by improving water supplies, sanitation and hygiene, and over 840,000 lives saved from diarrhea alone.
Recent breakthroughs in hydrophobic technology may have brought us a step closer to that goal. In January, Drs. Chunlei Guo and Anatoliy Vorobyev announced that they had succeeded in creating super-hydrophobic metal – that is, metal which strongly repels water. This is done through shooting a hugely powerful laser (the same amount of energy as the entire power grid of North America) at the metal for one quadrillionth of a second. The result is metal which water will actually bounce on and then roll off. Not only that, but when it goes, the water will also take other particles on the metal’s surface along for the ride, making it incredibly easy to clean.
The potential implications of this are huge. If – and it’s a big if – technology can be developed to allow hydrophobic metal to be mass produced, Dr. Guo believes it could be used to dramatically improve the hygiene of latrines in the Global South.
Beyond latrines, another major problem in the Global South are poor water delivery systems, which may seep wastewater and sewage into the surrounding environment, or may allow unsafe water from the environment to mix with drinking water. Hydrophobic pipes could conceivably help with both problems.
The possible benefits of hydrophobic materials extend well beyond improved sanitation, however. Across the world, thousands of people displaced by conflict or disasters are housed in emergency tents and temporary shelters, which often leak. Mattresses get wet, blankets and clothes are soaked, and there is no way to dry them. Not only does this make a terrible situation worse for many people, but it also puts them at risk of serious illnesses such as pneumonia.
A hydrophobic nanoscale coating, developed at the University of Michigan, could provide an answer to this. If emergency tents and blankets could be treated with the hydrophobic coating, and made almost completely resistant not only to water but also, presumably, to becoming sodden from snow, it would make a major difference in the quality of life for many of the world’s most vulnerable people. In addition to being drier, and therefore warmer, and easier to clean, hydrophobic tents and blankets might also be more durable (as they would not suffer water damage) and not need replacing as often, freeing up resources for other purposes.
It goes without saying that all of these applications are a long way off. Early signs are promising, however, and humanitarian organisations such as the Bill and Melinda Gates Foundation are already backing Dr. Guo’s invention.
To find out more you can read Guo and Vorobyev’s paper here, and watch the video below.