‘Jellybots’ offer hope for study of fragile coral reefs
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Soft, jellyfish-like robots that can fit through holes smaller than their bodies have been developed by scientists from Florida Atlantic University.
Their creators believe they could act as “guardians of the oceans” and can monitor fragile coral reefs without causing any damage.
The robots move through their surroundings using hydraulic-powered tentacles and have already been tested squeezing through holes cut in an acrylic-glass plate.
“Studying and monitoring fragile environments, such as coral reefs, has always been challenging for marine researchers. Soft robots have great potential to help with this,” said Dr Erik Engeberg, one of the robot’s inventors.
“Biomimetic soft robots based on fish and other marine animals have gained popularity in the research community in the last few years. Jellyfish are excellent candidates because they are very efficient swimmers.
“Their propulsive performance is due to the shape of their bodies, which can produce a combination of vortex, jet propulsion, rowing, and suction-based locomotion.”
The design of the jellybot is based on the shape of the moon jellyfish (Aurelia aurita) during the larval stage of its lifecycle.
To allow the robot to swim and steer the team used a hydraulic system driven by two impeller pumps.
Pumped water from the surrounding environment is used to inflate the jellybot’s eight silicone rubber tentacles to produce a swimming stroke.
When the pumps are not powered, the tentacles’ natural elasticity pushes the water back out.
Engeberg said: “A main application of the robot is exploring and monitoring delicate ecosystems, so we chose soft hydraulic network actuators to prevent inadvertent damage.
“Additionally, live jellyfish have neutral buoyancy. To mimic this, we used water to inflate the hydraulic network actuators while swimming.”
Five jellybots with varying levels of hardness were produced for the tests using 3D printing techniques.
“We found the robots were able to swim through openings narrower than the nominal diameter of the robot,” he said.
Future robots will have environmental sensors and navigational programming to help them find gaps and decide if they can swim through them.
In June MIT researchers developed a technique for transforming wetsuits into “artificial blubber”, allowing divers to remain in frigid water for three times longer than was previously possible.