Mia Heller is 18 years old, lives in Warrington, Virginia, and has invented a water filter that removes 96 percent of microplastics from drinking water using a magnetic oil and a clever self-recycling system she built herself in her garage and kitchen. The idea started when her local newspaper reported that her neighborhood’s water was contaminated with microplastics and harmful chemicals, and that residents would have to handle filtration on their own. Her parents installed a commercial system, but Mia watched her mother replace its membranes constantly and decided she could build something better, specifically a filter that required no solid membranes at all and could maintain itself by cycling its own materials in a closed loop.
The key ingredient is ferrofluid, a reusable magnetic oil that binds to microplastic particles as water flows through the system. Mia’s prototype works in three modules roughly the size of a bag of flour: one holds contaminated water, one stores the ferrofluid, and a third smaller chamber is where a magnetic field pulls microplastics out of the water while the ferrofluid is recovered and sent back around to be used again. After five rounds of iteration, the device removed 95.52 percent of microplastics from test water and recycled 87 percent of its ferrofluid, results that match or beat municipal water treatment plants, which typically remove between 70 and 90 percent. A toxicologist at the University of New Mexico called the invention a really great idea that is doing something that truly needs to be done, and Mia earned a special award at the Regeneron International Science and Engineering Fair, the world’s largest high school science competition, for her low-cost, low-waste approach. She plans to continue refining the device and says her eventual goal is to bring it to market as an affordable under-the-sink filtration system for everyday homes.
