RT Journal Article SR Electronic T1 Manta rays feed using ricochet separation, a novel nonclogging filtration mechanism JF Science Advances JO Sci Adv FD American Association for the Advancement of Science SP eaat9533 DO 10.1126/sciadv.aat9533 VO 4 IS 9 A1 Divi, Raj V. A1 Strother, James A. A1 Paig-Tran, E. W. Misty YR 2018 UL http://advances.sciencemag.org/content/4/9/eaat9533.abstract AB Solid-liquid filtration is a ubiquitous process found in industrial and biological systems. Although implementations vary widely, almost all filtration systems are based on a small set of fundamental separation mechanisms, including sieve, cross-flow, hydrosol, and cyclonic separation. Anatomical studies showed that manta rays have a highly specialized filter-feeding apparatus that does not resemble previously described filtration systems. We examined the fluid flow around the manta filter-feeding apparatus using a combination of physical modeling and computational fluid dynamics. Our results indicate that manta rays use a unique solid-fluid separation mechanism in which direct interception of particles with wing-like structures causes particles to “ricochet” away from the filter pores. This filtration mechanism separates particles smaller than the pore size, allows high flow rates, and resists clogging.