Robotically Controlled Jellyfish: Modifying Swimming Dynamics with Mechanical Forebodies

Ocean monitoring tools yield extensive data for understanding climate change but energy consumption is a limiting factor for mission duration. In contrast, Aurelia aurita jellyfish have a cost of transport 97% lower than some underwater vehicles and are adaptable to a wide range of ocean environments. Here we explore mechanically modifying jellyfish bells with added forebodies to reduce drag on swimming animals. By equipping jellyfish with microelectronic swim controllers, we create an ocean monitoring tool capitalizing on jellyfish regenerative capabilities paired with inexpensive electronics. Previous work has demonstrated stimulated jellyfish vertical swimming speeds of 2.8 times baseline speeds without swim controllers. We model the unsteady swimming dynamics of jellyfish with attached forebodies to study the impact of changes in drag and added mass on the animal dynamics. To inform this model, we conduct drop tests of various hemiellipsoid forebodies to empirically determine drag at terminal velocity. We validate the model by attaching forebodies onto the jellyfish exumbrellar surface to create a more streamlined shape. We utilize a 6m tall water tank to test the animal’s swimming speed and endurance experimentally with attached 3D printed caps.