Robojelly gets an upgrade

November 22, 2011
Robojelly gets an upgrade

Engineers at Virginia Polytechnic Institute and State University (VirginiaTech) have developed a robot that mimics the graceful motions of jellyfish so precisely that it has been named Robojelly. Developed for the Office of Naval Research in 2009, this vehicle was designed to conduct ocean underwater surveillance, enabling it potentially to detect chemical spills, monitor the presence of ships and submarines, and observe the migration of schools of fish.

Recently, a team at VirginiaTech has improved the performance of this silicone swimmer, enabling it to better overcome the limitations of its and better mimic the true motion of a jellyfish. Details on this new design and how it might provide new insights into jellyfish propulsion mechanisms will be presented at the 2011 meeting of the American Physical Society's Division of in Baltimore, Md., Nov. 20-22.

According to VirginiaTech Alex Villanueva, Robojelly looks very similar to an actual jellyfish. "Its geometry is copied almost exactly from a moon jellyfish [Aurelia aurita]," he said. The robot is built out of silicone and uses shape memory alloy (SMA) actuators to swim.

To move through the water, the natural animal uses the bell section of its body, which deforms and contracts to provide thrust. The lower, or lagging, section of the bell is known as the flexible margin, and it deforms slightly later in the swimming process than the rest of the bell. Until recently, however, Robojelly lacked this crucial piece of anatomy in its design.

Villanueva and his colleagues tested a number of different designs for their robot, some with and without an analog to a flexible margin. Initially, the used in construction presented a problem. Unlike their natural counterparts, the artificial materials tended to fold as they deformed, reducing Robojelly's performance.

After testing a number of designs and lengths for the folding margin, the engineers discovered that cutting slots into the bell reduced this unwanted folding effect.

This gave Robojelly a truer swimming stroke, as well as a big boost in speed.

"These results clearly demonstrate that the flap plays an important role in the propulsion mechanism of Robojelly and provides an anatomical understanding of natural ," said Villanuerva.

Explore further: Dutch zoo breeds own jellyfish

More information: The talk, "Effects of a flexible margin on Robojelly vortex structures," is on Tuesday, Nov. 22, 2011. Abstract: http://absimage.aps.org/image/MWS_DFD11-2011-001706.pdf

Related Stories

Dutch zoo breeds own jellyfish

September 29, 2007

Marine biologists at a Dutch zoo say they have succeeded in the difficult task of breeding jellyfish in captivity.

Jellyfish Robot Swims Like its Biological Counterpart

June 26, 2009

(PhysOrg.com) -- "Jellyfish are one of the most awesome marine animals, doing a spectacular and psychedelic dance in water," explain engineers Sung-Weon Yeom and Il-Kwon Oh from Chonnam National University in the Republic ...

Spanish resort in jellyfish alert

May 27, 2011

Authorities in the Spanish tourist hotspot of Benidorm said Friday they have reopened its beaches to tourists after removing more than a tonne of dangerous jellyfish.

Jellyfish replacing fish in over-exploited areas

September 16, 2011

(PhysOrg.com) -- Over-fished commercial stocks of plankton-eating fish have been replaced in several locations by jellyfish species. This appears to be something of a paradox because fish move quickly and can see their prey, ...

Swimming jellyfish may influence global climate

November 1, 2011

Swimming jellyfish and other marine animals help mix warm and cold water in the oceans and, by increasing the rate at which heat can travel through the ocean, may influence global climate. The controversial idea was first ...

Recommended for you

Team develops targeted drug delivery to lung

September 2, 2015

Researchers from Columbia Engineering and Columbia University Medical Center (CUMC) have developed a new method that can target delivery of very small volumes of drugs into the lung. Their approach, in which micro-liters ...

Not another new phone! But Nextbit's Robin is smarter

September 2, 2015

San Francisco-based Nextbit wants you to meet Robin, which they consider as the smarter smartphone. Their premise is that no one is making a smart smartphone; when you get so big it's hard to see the forest through the trees. ...

Team creates functional ultrathin solar cells

August 27, 2015

(Phys.org)—A team of researchers with Johannes Kepler University Linz in Austria has developed an ultrathin solar cell for use in lightweight and flexible applications. In their paper published in the journal Nature Materials, ...

Magnetic fields provide a new way to communicate wirelessly

September 1, 2015

Electrical engineers at the University of California, San Diego demonstrated a new wireless communication technique that works by sending magnetic signals through the human body. The new technology could offer a lower power ...

6 comments

Adjust slider to filter visible comments by rank

Display comments: newest first

Isaacsname
4.7 / 5 (3) Nov 22, 2011
It'd be nice to have a video , at the least.

You guys ever see this one ?

http://www.youtub...itFkSNtk
antialias_physorg
5 / 5 (1) Nov 22, 2011
this vehicle was designed to conduct ocean underwater surveillance, enabling it potentially to detect chemical spills, monitor the presence of ships and submarines, and observe the migration of schools of fish.


Awww. Doesn't that sound nice.

(...not to mention they'll find it useful for infiltration, placing mines, etc.)
It's the underwater version of the Predator drone.

Not knocking the technology - I think it's pretty awesome...but these euphemistic descriptions of what they want the thing to do - coming from the Office of Naval Research - are just so ridiculous.
Why don't they just admit what they want to do with it? No one is fooled.
moj85
5 / 5 (1) Nov 22, 2011
Also, whats to stop a shark from tearing this thing apart?
Nerdyguy
1.9 / 5 (9) Nov 22, 2011
this vehicle was designed to conduct ocean underwater surveillance, enabling it potentially to detect chemical spills, monitor the presence of ships and submarines, and observe the migration of schools of fish.


Awww. Doesn't that sound nice.

(...not to mention they'll find it useful for infiltration, placing mines, etc.)
It's the underwater version of the Predator drone.

Not knocking the technology - I think it's pretty awesome...but these euphemistic descriptions of what they want the thing to do - coming from the Office of Naval Research - are just so ridiculous.
Why don't they just admit what they want to do with it? No one is fooled.


From the National Academies of Science. Your predilection towards making overly dramatic and accusatory statements about all things U.S. & military will sometimes lead you down the wrong path. Bottom line, ONR does lots of non-military science.

http://www.nap.ed...mp;page=
antialias_physorg
not rated yet Nov 23, 2011
ONR does lots of non-military science

So does the NIF (the fusion experiments going on there come all under the heading of optimizing bombs through better fusion simulation).
If you look at their mission statements they're military installations/organisations. Do you really think anything that is financed through the DoD doesn't at least get looked at in terms of its military implications (or even gets started if it doesn't at least have some marginal relevance to it)?

What do you think they are? A bunch of altruists?

They're
Nerdyguy
1.5 / 5 (8) Nov 23, 2011
ONR does lots of non-military science

...Do you really think anything that is financed through the DoD doesn't at least get looked at in terms of its military implications (or even gets started if it doesn't at least have some marginal relevance to it)?

What do you think they are? A bunch of altruists?


No. Altruism has nothing at all to do with it. Congress has mandated that a certain amount of dollars go towards research where the objective is non-military civilian-side transfer. It's all there on the site I linked above.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.