Project:	Propulsive efficiency of robotically controlled jellyfish for ocean exploration
Disciplines:	Mechanical Engineering, Bioengineering, Physics, Aerospace
Mentor:	John Dabiri, Centennial Professor of Aeronautics and Mechanical, (EAS), jodabiri@caltech.edu
AO Contact:	Simon Anuszczyk, Simona@caltech.edu
Background:	Propulsive efficiency is a limiting factor for mission duration of ocean monitoring tools. In contrast, Aurelia aurita jellyfish have a propulsive efficiency 97% lower than some underwater vehicles and are adaptable to a wide range of ocean environments. Ocean monitoring tools could potentially capitalize on jellyfish regenerative capabilities and inexpensive electronics by equipping live jellyfish with microelectronic swim controllers. One key question is the energetics of biohybrid robotic jellyfish. We developed a method to experimentally investigate the energetics of long swimming durations commensurate with a dive to the deep ocean (e.g. greater than 6000m). While previous work found stimulated jellyfish vertical swimming speeds of up to 4.5 times baseline speeds without swim controllers, this is the first work to measure energetics during free-swimming experiments. We utilized a 6-meter tall water tank treadmill to characterize jellyfish swimming endurance and performance experimentally. These experiments inform an analytical model of stimulated jellyfish swimming dynamics and predict performance of jellyfish of different geometries. Future experiments aim to study the intra-stroke energetics of swimming biohybrid jellyfish on short timescales to understand where jellyfish expend the most energy during swimming.
Description:	Initial work will focus on utilizing particle image velocimetry (PIV) to investigate the wake dynamics of live jellyfish with robotic controllers. These measurements will enable the calculation of energetics and efficiency metrics for swimming animals throughout their swimming stroke. These experiments inform a better understanding of jellyfish biomechanics and capability as live ocean sensors.
References:	Biohybrid robotic jellyfish: https://www.science.org/doi/10.1126/sciadv.aaz3194 Electromechanical enhancement of biohybrid robotic jellyfish: https://iopscience.iop.org/article/10.1088/1748-3190/ad277f Wake measurements of jellyfish using PIV: https://doi.org/10.1242/jeb.034660
Student Requirements:	Prior Matlab experience required. Some experience working with PIV, live animals and animal biology highly encouraged.
Programs:	This AO can be done under the following programs:   Program    Available To        SURF    Caltech students only  Click on a program name for program info and application requirements.