After my recent experience at the Vancouver Aquarium (Jan.19.12 posting) where I was informed that jellyfish are now called sea jellies, I was not expecting to see the term jellyfish still in use. I gather the new name is not being used universally yet, which explains the title for a March 23, 2012 news item on Nanowerk, Robotic jellyfish built on nanotechnology,
Researchers at The University of Texas at Dallas and Virginia Tech have created an undersea vehicle inspired by the common jellyfish that runs on renewable energy and could be used in ocean rescue and surveillance missions.
In a study published this week in Smart Materials and Structures (“Hydrogen-fuel-powered bell segments of biomimetic jellyfish”), scientists created a robotic jellyfish, dubbed Robojelly, that feeds off hydrogen and oxygen gases found in water.
“We’ve created an underwater robot that doesn’t need batteries or electricity,” said Dr. Yonas Tadesse, assistant professor of mechanical engineering at UT Dallas and lead author of the study. “The only waste released as it travels is more water.”
Engineers and scientists have increasingly turned to nature for inspiration when creating new technologies. The simple yet powerful movement of the moon jellyfish made it an appealing animal to simulate.
The March 22, 2012 press release from the University of Texas at Dallas features images and a video in addition to its text. From the press release,
The Robojelly consists of two bell-like structures made of silicone that fold like an umbrella. Connecting the umbrella are muscles that contract to move.
Here’s a computer-aided image,
Here’s what the robojelly looks like,
This robojelly differs from the original model,which was battery-powered. Here’s a video of the original robojelly,
The new robojelly has artificial muscles(from the Mar. 22, 2012 University of Texas at Dallas press release),
In this study, researchers upgraded the original, battery-powered Robojelly to be self-powered. They did that through a combination of high-tech materials, including artificial muscles that contract when heated.
These muscles are made of a nickel-titanium alloy wrapped in carbon nanotubes, coated with platinum and housed in a pipe. As the mixture of hydrogen and oxygen encounters the platinum, heat and water vapor are created. That heat causes a contraction that moves the muscles of the device, pumping out the water and starting the cycle again.
“It could stay underwater and refuel itself while it is performing surveillance,” Tadesse said.
In addition to military surveillance, Tadesse said, the device could be used to detect pollutants in water.
This is a study that has been funded by the US Office of Naval Research. At the next stage, researchers want to make the robojelly’s legs work independently so it can travel in more than one direction.