This robotic jellyfish is a climate spy | Science News for Students

This robotic jellyfish is a climate spy

Squishy tentacles let this gadget monitor coral reefs without disturbing them
Dec 18, 2018 — 6:45 am EST
robo-jellyfish

A soft and squishy robo-jellyfish pumps its way gently through the ocean, providing little or no disturbance to local sea life.

Jennifer Frame, Nick Lopez, Oscar Curet and Erik D. Engeberg/IOP Publishing

This is one in a series presenting news on technology and innovation, made possible with generous support from the Lemelson Foundation.

To study coral reefs and the creatures that live there, scientists sometimes deploy underwater drones. But drones aren’t perfect spies. Their propellers can rip up reefs and harm living things. Drones also can be noisy, scaring animals away. A new robo-jellyfish might be the answer.

Erik Engeberg is a mechanical engineer at Florida Atlantic University in Boca Raton. His team developed the new gadget. Think of this robot as a quieter, gentler ocean spy. Soft and squishy, it glides silently through the water, so it won’t harm reefs or disturb animals living around them. The robot also carries sensors to collect data.

The device has eight tentacles made of soft silicone rubber. Pumps on the underside of the robot take in seawater and direct it into the tentacles. The water inflates the tentacles, making them stretch out. Then power to the pumps briefly cuts out. The tentacles now relax and water shoots back out of holes on the underside of the device. That rapidly escaping water propels the jellyfish upwards.

internal workings
This image shows some of the robot's internal components: (a) the circuit board used to control the jellyfish, (b) the two pumps used to control the tentacles mounted onto the underside of the jellyfish, and (c) the other electronics held within the central canister.
Jennifer Frame, Nick Lopez, Oscar Curet and Erik D. Engeberg/IOP Publishing

The robot also has a hard, cylindrical case on top. This holds the electronics that control the jellyfish and store data. One component allows wireless communication with the jellyfish. That means someone can remotely steer the robot by making different tentacles move at different times. The hard case could hold sensors, too.

Engeberg’s group described its robot’s design September 18 in Bioinspiration & Biomimetics.

Natural inspiration

The researchers had practical reasons for modeling their device on jellyfish. “Real jellyfish only need small amounts of power to travel from [point] A to B,” Engeberg says. “We wanted to really capture that quality in our jellyfish.”

Jellyfish move slowly and gently. So does the robo-jelly. That’s why the researchers think it won’t frighten marine animals. What’s more, Engeberg says, “The soft body of our jellyfish helps it to monitor ecosystems without damaging them.” For example, the robot could carry a sensor to record ocean temperatures. The data it gathered could help scientists map where and when the ocean is warming because of climate change.

coral reef
Coral reefs are the backbone of a diverse ecosystem. That’s one reason scientists are working hard to understand what it takes to keep them healthy.
VitalyEdush/iStockphoto

“Jellyfish have been moving around our oceans for millions of years, so they are excellent swimmers,” says David Gruber. He’s a marine biologist at Baruch College in New York City who was not involved with the robot. “I’m always impressed when scientists get ideas from nature,” Gruber says. “Especially something as simple as the jellyfish.”

Fighting climate change motivates Engeberg and his team. “I have a deep desire to help endangered reefs around the world,” he says. He hopes his robo-jellyfish will help researchers study the otherwise hidden impacts of climate change at sea.

Tracking sea temperatures and other data can benefit people, too, by warning of worsening conditions. Warmer oceans can make storms more powerful and destructive. Warmer seawater also helps melt sea ice by eroding glaciers from below. That meltwater adds to rising sea levels. And higher seas can lead to coastal flooding, or make low-lying islands disappear altogether.

The robotic jellyfish is a work in progress. We are making a new version right now,” Engeberg says. It swims deeper and can carry more sensors than the older model. This should make it an even better spy on the conditions affecting coral reefs worldwide.

Power Words

(more about Power Words)

Atlantic     One of the world’s five oceans, it is second in size only to the Pacific. It separates Europe and Africa to the east from North and South America to the west.

biology     The study of living things. The scientists who study them are known as biologists.

climate     The weather conditions that typically exist in one area, in general, or over a long period.

climate change     Long-term, significant change in the climate of Earth. It can happen naturally or in response to human activities, including the burning of fossil fuels and clearing of forests.

coral     Marine animals that often produce a hard and stony exoskeleton and tend to live on reefs (the exoskeletons of dead ancestor corals).

drone     A remote-controlled, pilotless aircraft or missile.

ecosystem     A group of interacting living organisms — including microorganisms, plants and animals — and their physical environment within a particular climate. Examples include tropical reefs, rainforests, alpine meadows and polar tundra. The term can also be applied to elements that make up some an artificial environment, such as a company, classroom or the internet.

engineer     A person who uses science to solve problems. As a verb, to engineer means to design a device, material or process that will solve some problem or unmet need.

glacier     A slow-moving river of ice hundreds or thousands of meters deep. Glaciers are found in mountain valleys and also form parts of ice sheets.

global warming     The gradual increase in the overall temperature of Earth’s atmosphere due to the greenhouse effect. This effect is caused by increased levels of carbon dioxide, chlorofluorocarbons and other gases in the air, many of them released by human activity.

marine biologist     A scientist who studies creatures that live in ocean water, from bacteria and shellfish to kelp and whales.

mechanical     Having to do with the devices that move, including tools, engines and other machines (even, potentially, living machines); or something caused by the physical movement of another thing.

mechanical engineer     Someone trained in a research field that uses physics to study motion and the properties of materials to design, build and/or test devices.

meltwater     The water that comes from melting ice. The quantities can be large and show up quickly when it comes from melting glaciers, ice sheets and snow-capped mountains.

model     A simulation of a real-world event (usually using a computer) that has been developed to predict one or more likely outcomes. Or an individual that is meant to display how something would work in or look on others.

monitor     To test, sample or watch something, especially on a regular or ongoing basis.

reef     A ridge of rock, coral or sand. It rises up from the seafloor and may come to just above or just under the water’s surface.

robot     A machine that can sense its environment, process information and respond with specific actions. Some robots can act without any human input, while others are guided by a human.

sea     An ocean (or region that is part of an ocean). Unlike lakes and streams, seawater — or ocean water — is salty.

sea level     The overall level of the ocean over the entire globe when all tides and other short-term changes are averaged out.

seawater     The salty water found in oceans.

sensor     A device that picks up information on physical or chemical conditions — such as temperature, barometric pressure, salinity, humidity, pH, light intensity or radiation — and stores or broadcasts that information. Scientists and engineers often rely on sensors to inform them of conditions that may change over time or that exist far from where a researcher can measure them directly. (in biology) The structure that an organism uses to sense attributes of its environment, such as heat, winds, chemicals, moisture, trauma or an attack by predators.

Citation

Journal: J. Frame et al. Thrust force characterization of free-swimming soft robotic jellyfish. Bioinspiration & Biomimetics. Published online September 18, 2018. doi: 10.1088/ 1748-3190/aadcb3.