Sitting around their office late one night, Pennington, Miller, and Dillman began brainstorming things that perform filtering functions naturally. They landed on fish. Manta rays have cone-like mouths with parallel arrays of ridged lobes that cause plankton to ricochet off the filter walls and funnel straight down the ray’s throat, allowing water to separate into their gills. They studied the existing research on the physics of just how these filter-feeding fish separate food from water, then used that process as a model. Other researchers, like a team at MIT that got inspiration from mobula rays to inform water filter improvements, have looked to filter feeding fish to help guide engineering breakthroughs.
As soon as they started printing 3D designs inspired by the fishes’ mouths, they realized they had found a solution. Their patented technology, called Vortx, creates small vortices that separate and suspend microplastics and other particles in the center of the filter, reducing the amount of clogging that occurs. The plastics then flow to the back of the Cleanr filter into a disposable pod, making the design easy for consumers to use. The filter, sold directly to consumers for $299, is external and sits on top of or next to a washing machine.
Cleanr’s filter removes over 90 percent of microplastics released in each wash cycle, collecting particles as small as 50-microns, or around the width of a piece of hair. Pennington says it also clogs less than other filters. In fact, one of Cleanr’s early prototypes flooded Pennington’s college apartment. Another became clogged with dog hair. After that result, the team began sourcing dog hair from local groomers to test future prototypes.
Though Cleanr’s filter is innovative, it still faces competition. Other microfiber filters and solutions are already on the market, and more are on the way. The Cora Ball, a sphere layered with plastic coils, removes 30 percent of microplastics per load, while the Guppyfriend Bag, a mesh sack used to hold clothes, reduces between 80 and 100 percent. The PlanetCare, another external filter, reduces 98 percent per load—though it can be challenging to install and may not work well for pet owners. Meanwhile, researchers in Japan have successfully used sound waves to filter out microfibers.