The process of removing salt water and particulate matter from ocean water to make it potable—desalination—can be tricky, time consuming, require a lot of fancy equipment, and use more energy than most water-deprived areas have to spare. Lockheed Martin has announced the creation of a new salt filter which they say could cut energy usage by up to 20 percent. This breakthrough could be the step that makes desalination a viable practice for serving water scarce regions of the world that also suffer from energy shortages.
Lockheed calls the filtering material Perforene and patented the membrane in 2013 for use in the oil industry. It’s made from a thin layer of graphene, a carbon-based material known for its incredible strength and durability. The filter is so thin, in fact, that it measures just a single atom in thickness. Because of this, the desalination process doesn’t require the intense pressure ordinarily needed to push water through a thick filter. Lockheed’s new development effectively creates a shortcut in the process, saving time and energy.
The genius in the design is that the holes in the filter are just 100 nanometers in diameter, which is large enough to allow water molecules to squeeze through, but too small for salt particles. The Lockheed engineer credited with the invention, John Stetson, says the new filter has a lot of benefits. “It’s 500 times thinner than the best filter on the market today and a thousand times stronger,” Stetson explained to Reuters. “The energy that’s required and the pressure that’s required to filter salt is approximately 100 times less.”
Ironically, despite graphene’s amazing strength—some 1,000 times stronger than steel—the ultrathin filters are prone to tearing. Lockheed is currently working out the kinks to prevent that problem, as well as find ways to ramp up production so the new micro desalination filters can start providing clean drinking water for people in need as quickly as possible.