Most water filters take advantage of the working principle of the sieve. The key part is the filtration membrane pore that cannot allow large particles to pass through. But one of the big problems with this filter is that sooner or later the filter will be blocked by the particles it adsorbs. The good news is that bionic studies of manta rays promise a better solution. Although it looks a bit "casual", manta rays are actually harmless to humans and animals. They feed entirely on plankton and miniature crustaceans, which require a biologically robust seawater filtration system.
Manta rays foraging with their mouths open (Image: Wikipedia)
Fish that feed with filtration usually swallow water into their mouths and then force their work with the help of gills. In the effluent path, water passes through densely arranged hook-lined appendages (called gill rakers), which plankton cannot get out of because of their larger size.
It is worth mentioning that when the discharged water flow passes, a vortex is formed, causing the plankton to pop out of the leaf and return to the mouth. This improved structure allows the gill raker to be more than just a capture filter, but also to repel particles.
Not only does this mean that the system is fairly resistant to clogging, it can also operate at high flow rates, and allows animals to retain prey that is much smaller than gill raker gaps.
Manta rays have a unique gill raker structure with long, parallel leaf-like arrays (Credit: Oregon State University)
Jim Strother, a co-author and assistant professor, said:
We are currently studying whether this mechanism can be engineered and used in areas such as wastewater treatment in the future to address the new threat posed by microplastics.
Details of the study have been published in the recent journal Science Advances. The original title reads:
《manta rays feed using ricochet separation, a novel nonclogging filtration mechanism》 (Bounce separation of gill rakers, a novel non-clogging filtration mechanism)
[Compiled from: new atlas]