Virginia Tech College of Engineering researchers are part of a national study that has cracked how jellyfish move with the lowest cost of transport of any animal. The findings will be used as researchers continue to design bio-inspired jellyfish for the U.S. Navy.
Published in a recent issue of the Proceedings of National Academy of the Sciences, the study highlights jellyfish as one of the most energetically efficient natural propulsors on the planet. Researchers found that rather than moving continuously through water while swimming, jellyfish use a critical pause between the contraction and expansion of their bell-shaped body to create a vortex that pushes them forward. In essence, the creature displaces the water behind them, creating a "hole" that when re-filled propels them forward.
This feat of motion allows the creature to travel 30 percent farther each stroke cycle, thereby reducing metabolic energy demand by swimming muscles, said Shashank Priya, professor of mechanical engineering and Turner Fellow, who led Virginia Tech efforts on the project. "The fluid is helping the jellyfish to move and conserve the energy," he said. "The fluid is actually pushing them, and when that energy dissipates, they contract again."
Researchers also found that the jellyfish in the study displayed a lower cost of transport the amount of food and oxygen taken in by the body, versus energy spent in movement 48 percent lower than other animals in similar studies. This quick action with minimal spent also helps jellyfish in hunting of food.
The study was led by the Marine Biological Laboratory, based in Woods Hole, Mass., along with Virginia Tech; Providence College and Roger Williams University, both of Rhode Island; and California Institute of Tec
|Contact: Steven Mackay|