Deep-Sea Soft Bionic Fish: Advances in Pressure-Tolerant Design, Soft Actuation, and Autonomous Systems

Area of Science:

• Robotics
• Oceanography
• Materials Science

Background:

• Flexible robotic fish offer compliant bodies and low-disturbance propulsion for deep-sea exploration.
• Deep-sea environments present challenges including high pressure, low temperature, darkness, and limited communication.

Purpose of the Study:

• To synthesize research on deep-sea flexible robotic fish, covering soft robotics, bio-inspiration, actuation, packaging, sensing, and control.
• To organize literature around a system-level design chain from biological inspiration to control strategies.

Main Methods:

• Literature synthesis across deep-sea soft robotics, bio-inspired robotic fish, smart-material actuation, pressure-adaptive packaging, multimodal sensing, and autonomous control.
• Organizing research around biological mechanisms, body architectures, soft actuators, and control strategies.

Main Results:

• The central challenge lies in the co-design of pressure-adaptive bodies, hybrid soft actuation, reliable interfaces, multimodal perception, energy management, and autonomy.
• The review provides design-principle abstraction, actuator-selection guidance, prototype comparison, failure-mode analysis, and a computational design workflow.

Conclusions:

• Future research should focus on long-term reliability, standardized deep-sea evaluation protocols, physics-informed modeling, and integrated prototype demonstrations.
• Successful deep-sea robotic fish require integrated co-design of multiple critical systems for robust performance.