A gelatinous sea creature might educate engineers a lesson or two.
Nanomia bijuga, a marine animal associated to jellyfish, swims by way of jet propulsion. A dozen or extra squishy constructions on its physique pump water backward to push the animal ahead. And it could possibly management these jets individually, both syncing them up or pulsing them in sequence.
A staff of UO researchers discovered that these two completely different swimming types let the animal prioritize pace or power effectivity, relying on its present wants. The invention might inform underwater car design, serving to scientists construct extra sturdy automobiles that may carry out effectively beneath varied situations.
The UO staff, led by marine biologist Kelly Sutherland and postdoctoral researcher Kevin Du Clos, report their findings in a latest paper in Proceedings of the Nationwide Academy of Sciences.
“Most animals can both transfer rapidly or in a approach that’s energetically environment friendly, however not each,” Sutherland stated. “Having many distributed propulsion items permits Nanomia to be each quick and environment friendly. And, remarkably, they do that with out having a centralized nervous system to manage the completely different behaviors.”
Nanomia shares the gelatinous, ethereal type of its jellyfish family members. Nevertheless it’s just a little extra structurally sophisticated: Each is technically a colony of people. As an example, every of Nanomia’s jets is produced by a person unit referred to as a nectophore. The nectophores are clustered on a stalk-like construction on the entrance of the animal. In the meantime, wispy tentacles path behind, carrying constructions specialised for feeding, copy, and safety.
Whereas many marine creatures transfer by way of jet propulsion, squid and jellyfish included, most have one jet. Nanomia usually has 10 to twenty; the precise quantity varies from colony to colony.
“We’re fascinated by why multijet swimming is helpful, and what we have been fascinated by right here was the timing,” Du Clos stated.
Nanomia can pulse its nectophores or activate them in a sequence. Du Clos and his colleagues needed to see how these completely different modes affected the animals’ swimming model, presumably illuminating an evolutionary benefit to having a number of jets.
At Friday Harbor Labs in Washington, the researchers scooped Nanomia out of the ocean and put them in tanks within the lab. Then they used video recordings and laptop fashions to investigate the swimming patterns.
The staff discovered that the 2 swimming modes are suited to completely different conditions.
Synchronous pulsing sends Nanomia ahead in a short time, good for an expeditious escape from a predator. Asynchronous pulsing strikes the animal slowly however steadily, and the researchers’ modeling experiments advised it’s a extra energy-efficient method to swim. So with Nanomia generally touring tons of of meters each day, asynchronous pumping could be higher suited to on a regular basis use.
The intricacies of Nanomia’s motion might be helpful for engineers turning to nature for inspiration.
“It provides a framework for growing a robotic with a variety of capabilities,” Du Clos stated.
As an example, an underwater car might have a number of propulsors, and easy modifications in propulsion timing might enable that one car to maneuver both rapidly or effectively as the necessity arises.
In future work, the researchers plan to dive extra into Nanomia’s options, specializing in higher understanding how the association of the animal’s tentacles impacts its feeding.
Sutherland added that colonial animals are fairly widespread within the open sea resulting from their potential hydrodynamic benefits. The staff is at present trying past Nanomia at different species of colonial swimmers to determine how various preparations of swimming items affect animals’ motion.
Supply: University of Oregon