ABSTRACT Traditional rigid submersibles often lack the acoustic stealth and agility required for close‐range deep‐sea exploration. While soft robotics have emerged as a promising approach for navigating complex marine environments, these systems typically face a trade‐off between pressure tolerance and practical maneuverability. We present DeepTrack, an untethered soft robotic fish driven by a compact electromagnetic propulsion system. Integrating a pressure‐independent actuation mechanism into a compliant silicone body keeps the robot's mass at just 475 g and eliminates the need for bulky pressure vessels. A two‐fin configuration decouples forward propulsion from depth regulation, enabling agile 3D maneuvering. An onboard visual servoing system ensures precise closed‐loop target tracking. Experimental validations demonstrated a maximum swimming speed of 5.78 cm/s (0.27 body length (BL)) and a yaw rate of 0.26 rad/s. During dynamic trajectory tracking, the system maintained a root mean square error (RMSE) below 0.37 BL. Open‐water field trials further validated the robot's robustness in autonomously tracking dynamic targets amid ambient currents and unstructured visual clutter. Furthermore, hyperbaric chamber tests confirm that the robot preserves its structural integrity and tracking performance at hydrostatic pressures up to 30 MPa. These results demonstrate the potential of DeepTrack as a mechatronic platform for future visually guided operations in deep sea environments.
Wang et al. (Wed,) studied this question.