Researchers from the Max Planck Institute for Intelligent Systems have designed a tiny soft robot that mimics jellyfish and their movement through water. Jellyfish are graceful marine creatures that pulsate their umbrella-shaped bells to push them through water and can use a similar motion to pull the water beneath them, allowing them to catch food. The “Jellyfishbot” features that same umbrella-shaped bell and trailing tentacles as its natural counterpart, and uses them in a near identical manner for motion and grasping objects.
In a recently published paper entitled “Multi-functional soft-bodied jellyfish-like swimming,” the scientists describe how they designed the Jellyfishbot, which is about five millimeters in size. The robot’s bell-shaped body was created using a series of nonmagnetic elastomer lappets (or arms), eight of them in total. Embedded in those arms are tiny magnetic particles, which actuate the arms when exposed to an external oscillating magnetic field — for example, they can manipulate the bell in a sequence that enables the robot to float upwards, downwards, and side to side.
To help the robot maintain its orientation while moving through water, the researchers positioned a bubble of air in the top of the bell, which allows it to retain a neutral buoyancy as well. The team studied baby jellyfish from the scyphomedusae ephyra species, capturing detailed data on their movement, and applied that data to the design of the Jellyfishbot. By manipulating the magnetic field’s strength, the scientists found they could grab and move small objects, and even bury the robot in a mass of beads at the bottom of their test tank.
The researchers envision employing the Jellyfishbot to help answer environmental questions, such as what the impact might be on real jellyfish if there are changes to ocean currents and temperatures. They could also have potential uses for medical applications, such as providing internal ultrasound imaging or deliver drugs to cancerous tissue.