Underwater Vehicles Take on Jellyfish Form
The effort to design this bio-inspired vehicle arose out of the Navy’s desire to create a network of underwater sensors that could move like animals in the ocean. Researchers from Virginia Tech, Stanford, UCLA, University of Texas at Dallas and Providence College have collaborated on the project.
The resulting vehicle, dubbed Robojelly, mimics the muscle movements of an actual jellyfish and runs on hydrogen and oxygen gases found in the water. The goal is for the robot to swim like a jellyfish and hold its position in the ocean for surveillance purposes. The machine was modeled after the Cyanea genus of jellyfish found in the northern Atlantic and Pacific oceans.
“It looks like a very large jellyfish,” says Jack Costello, biology professor at Providence College. “We tried different species, but this one seemed to be the best matchup between materials and the way it swims, and it has a number of external resemblances to this specific type of jellyfish.”
One of the first prototypes researchers built measured only 10 centimeters wide. Robojelly is about 15 times that size.
The robot consists of commercial shape memory alloys, which are metals that remember and return to their original shapes. They are used to replicate actuators that change shape, elasticity and position based on temperature or electromagnetic fields. Robojelly so far has successfully performed these movements during tests inside a water tank.
Researchers continue to investigate the types of sensors that could go on the artificial jellyfish, and how they would collect and relay information from the environment to appropriate parties. The jellyfish sensors could be used in a variety of applications, including search-and-rescue missions.