Robot jellyfish to be environmental watchdog

8 Jan
Student team members from the Virginia Tech's National Science Foundation Center for Energy Harvesting Materials and Systems test a five-foot wide jellyfish-like robot under water at War Memorial Hall. Photo by:Amanda Loman, Virginia Tech

Student team members from the Virginia Tech’s National Science Foundation Center for Energy Harvesting Materials and Systems test a five-foot wide jellyfish-like robot under water at War Memorial Hall. Photo by:Amanda Loman, Virginia Tech

While jellyfish aren’t a beach goer’s favorite sea creature,  these blob-like organisms–or at least robotic prototypes designed to look and move just like them– could be used to patrol the ocean, looking for signs of environmental despair in the near future.

The variety of shapes, sizes and colors of jellyfish, as well as their low metabolic energy rate, is why researchers nominated these cnidarians to monitor the sea.

So far, Virginia Tech College of Engineering researchers have created two robotic prototypes of these jellyfish. The first robot, named RoboJelly was only about the size of a man’s hand and was designed to look like the jellyfish found near shore along beaches.

The second one designed by Shashank Priya,professor of mechanical engineering at Virginia Tech was unveiled in 2012, stands 5 foot 7 inces tall and weighs roughly 170 pounds. The giant robotic jellyfish was named Cyro, after the species it was designed to look like– Cyanea capillata, Latin for Llion’s Manemain.

Virginia Tech: Autonomous Robotic Jellyfish from virginiatech on Vimeo.

Alex Villanueva, a doctoral student in mechanical engineering working under Priya said that it is important that a variety of these prototypes be designed to be used for different purposes.

“A larger vehicle will allow for more payload, longer duration and longer range of operation,”  Villanueva said. “Biological and engineering results show that larger vehicles have a lower cost of transport, which is a metric used to determine how much energy is spent for traveling.”

The robots are part of a  $5 million project funded by U.S. Naval Undersea Warfare Center and the Office of Naval Research with the purpose of creating self-powered devices to monitor the oceans. While carefully measuring the health of the marine environment is the number one goal, these devices could also be used for other practical purposes such as mapping ocean floors, studying ocean currents and learning more about marine life.

Because jellyfish are present in just about every major part of the world’s oceans–including shallow water, as well as depths deeper than 7,000 meters–they were chosen as opposed to more attractive organisms such as beloved dolphins or sea turtles.

Currently, both robots are simply prototypes and have years before they can be employed into the sea.

“We hope to improve on this robot and reduce power consumption and improve swimming performance as well as better mimic the morphology of the natural jellyfish,” Villanueva said. “Our hopes for Cyro’s future is that it will help understand how the propulsion mechanism of such animal scales with size.”

Currently, the scientists are fixing kinks and working on getting the robots to operate on their own for months at a time. This needs to be done because once released, it will be difficult for researchers to locate and fix the robots or replace their batteries.

“Cyro showed its ability to swim autonomously while maintaining a similar physical appearance and kinematics as the natural species,” Priya said. “This autonomous operation in shallow water conditions is already a big step towards demonstrating the use of these creatures.”

Priya said the outside of the orgaanism was designed to feel squishy in one’s hand, just like a real jellyfish. But, the prototype has a rigid support system inside unlike the free-form structure of the authentic animal. The support structure includes direct current electric motors. These control the mechanical arms and are used in together with an artificial mesoglea, or jelly-based pulp of the fish’s body to create hydrodynamic movement.

“It has been a great experience to finally realize the biomimetic and bio-inspired robotic vehicles,” Priya said. “Nature has too many secrets and we were able to find some of them but many still remain. We hope to find a mechanism to continue on this journey and resolve the remaining puzzles.”

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