While architects often dream of floating houses and cities of the future, a new floating technology is promising to clean up our waterways. The winner of the 2014 Disrupt-O-Meter award is Puralytics, for the innovative technology that's at the root of the LilyPad, a floating, portable water purification device that works without chemicals, consumables, or power. How does it work? In a (big) word: Photocatalysis. When sunlight hits the nanotechnology-coated mesh that comprises the pad, it triggers a series of reactions that break down or remove pathogens in the water. Destroying pollutants—rather than collecting them, and in turn creating a hazardous waster condition—further enhances the LilyPad's green credentials. While other passive water-treatment methods—filters, purification tablets, and UV sterilizers—can dispatch with bacteria and protozoa, they don't address the truly nasty pollutants: heavy metals like lead and mercury, organic contaminants used in pesticides and herbicides, and pharmaceuticals. The LilyPad is still in development, undergoing rigorous field testing at Oregon State University's Stormwater Infrastructure Research Facility before it can be approved and deployed to clean up industrial waste-water, retention ponds, or streams. But it's possible to experience the process on a smaller scale right now. Puralytics manufactures a reusable three-liter sack, the SolarBag, that employs the same water-purifying technology.