Lyfish-inspired pumps: Researchers investigate next generation medical and robotic devices

November 23, 2010

To the causal aquarium visitor, the jellyfish doesn't seem to be a particularly powerful swimmer; compared to a fish, it glides slowly and peacefully.

But for Janna Nawroth, a graduate student at the California Institute of Technology in Pasadena, the undulations of this simple invertebrate hold secrets that may make possible a new generation of tiny pumps for medical applications and soft robotics -- work she describes today at the American Physical Society Division of (DFD) meeting in Long Beach, CA.

"Most pumps are made of rigid materials," says Nawroth. "For medical pumps inside the human body, we need flexible pumps because they move fluids in a much gentler way that does not destroy tissues and cells."

Nawroth is working with Caltech engineer John Dabiri, an expert on jellyfish propulsion. His research has shown these cnidarians tend to fall into two categories -- those that produce faster, harder strokes and those that create weaker but more efficient strokes. He has also studied the flows and eddies created by the strokes, which can be characterized by a dimensionless quantity called a Reynolds number.

"We're really lucky," says Nawroth. "The Reynolds numbers we see in the movement of jellyfish of different sizes and ages are in the right range as what we need for medical applications."

As a step towards creating flexible pumps, Nawroth is studying how jellyfish shape and tissue composition adapt to the demands imposed by flow conditions at different Reynolds numbers. Jellyfish at millimeter scales, for example, exploit the small layer of water that adheres to their surface as they move and use it as additional paddle at no extra cost. Further, a clever arrangement of multiple within the body allow for a reliable yet tunable pumping mechanism.

In the future, Nawroth plans to use this practical understanding to help design a whole spectrum of flexible pumps that are optimized for different tasks and conditions.

Explore further: Jellyfish is anatomically sophisticated

More information: The presentation, "Learning from jellyfish: Fluid transport in muscular pumps at intermediate Reynolds numbers" is on Tuesday, November 23, 2010
. Abstract:

Related Stories

Jellyfish is anatomically sophisticated

June 21, 2005

A U.S. study says the anus-less, headless, heartless, gutless, back or front-less jellyfish is really a remarkable genetically sophisticated creature.

When sea monsters threaten, eat them

December 7, 2005

Japanese fishermen report encountering an increasing number of "sea monsters" -- 6-foot-wide, 450-pound poisonous jellyfish.

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: Far from Passive Drifters-in-the-Currents

May 11, 2009

( -- If you were to snorkel just before dawn at the popular tropical Pacific destination Jellyfish Lake, you'd have lots of company: millions of golden jellyfish, known to scientists as Mastigias papua, mill around ...

Voracious comb jellyfish 'invisible' to prey

October 12, 2010

Despite its primitive structure, the North American comb jellyfish can sneak up on its prey like a high-tech stealth submarine, making it a successful predator. Researchers, including one from the University of Gothenburg, ...

Making use of jellyfish on dry land

November 8, 2010

John Dabiri, assistant professor of aeronautics and bioengineering at Caltech who won a MacArthur Award this year, is fascinated by jellyfish. He believes jellyfish propulsion can inform engineering, which in turn can inform ...

Recommended for you

The topolariton, a new half-matter, half-light particle

October 7, 2015

A new type of "quasiparticle" theorized by Caltech's Gil Refael, a professor of theoretical physics and condensed matter theory, could help improve the efficiency of a wide range of photonic devices—technologies, such as ...

Perfectly accurate clocks turn out to be impossible

October 7, 2015

Can the passage of time be measured precisely, always and everywhere? The answer will upset many watchmakers. A team of physicists from the universities of Warsaw and Nottingham have just shown that when we are dealing with ...

Professor solves 140-year fluid mechanics enigma

October 7, 2015

A Purdue University researcher has solved a 140-year-old enigma in fluid mechanics: Why does a simple formula describe the seemingly complex physics for the behavior of elliptical particles moving through fluid?

Fusion reactors 'economically viable' say experts

October 2, 2015

Fusion reactors could become an economically viable means of generating electricity within a few decades, and policy makers should start planning to build them as a replacement for conventional nuclear power stations, according ...


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.