MIT 3D Prints Water Filters Inspired by Manta Rays

Biology has long been a source of design inspiration—think of Leonardo da Vinci’s flying machine, a contraption with wings inspired by bats. Today, engineers continue the practice, often integrating models inspired by nature into 3D printed designs. In a new project, the Massachusetts Institute of Technology (MIT) 3D printed water filters inspired by manta rays. By deriving design principles from the rays, which go beyond traditional filtration systems, the team created manta ray-inspired water filtration devices.

Manta rays are filter-feeders, which means they strain their food from mouthfuls of seawater. MIT engineers realized that one family of manta rays in particular—the mobula ray—filters its food in a way that could be adopted in industrial water filters. These aquatic creatures swim with their mouths open through plankton-rich regions of the ocean, catching plankton in their gullets while water streams into their mouths and out through their gills.

MIT’s 3D printed filtration devices inspired by mobula rays (Photo credits: Jennifer Chu, MIT)

So what stops plankton from flowing out of the manta’s mouth through the gills? The mobula ray’s mouth is lined on either side with comb-like structures called plates that draw water into the ray’s gills. The MIT team believes that due to the dimension of these plates, incoming plankton may bounce off of them, flowing deeper into the manta’s cavity. The gills also absorb oxygen from the outflowing water, allowing the ray to breathe while feeding. One of the authors of the study, Anette “Peko” Hosoi, explained, “We show that the mobula ray has evolved the geometry of these plates to be the perfect size to balance feeding and breathing.”