Submersible Soft‐Robotic Platform for Noise‐Free Hovering Utilizing Liquid–Vapor Phase Transition

Abstract

Hovering at any depth, is one of the most important requirements for underwater robotics, which calls for large‐range buoyancy control ability. Although various underwater robotics have been proposed and developed, the requirements of noise‐free, environmental tolerance, and low energy consumption in hovering manipulation, are still attracting a lot of attention for underwater tasks. Herein, a submersible soft‐robotic platform driven by the self‐contained liquid–vapor phase transition is developed. The proposed soft‐robotic platform precisely modulates its buoyancy, showing an excellent positioning ability underwater. The proposed soft‐robotic platform performs reversible rise‐and‐sink motions underwater, and generate a buoyancy force of 0.93 N (131% of its weight) with an accuracy of ±2.5 mN, at a heating temperature of 63 °C. It shows that more than 40% of the total buoyancy change is achieved within 55 s, and the platform hovers in any depth in a range of 450 mm (limited by the adopted water container) in 18 s, with positioning fluctuation of 17.42 mm. This soft‐robotic platform demonstrates active vertical motions in water and suggests a feasible approach to develop noisy‐free and high‐reliability underwater robots, which guide the further design of autonomous underwater vehicles (AUVs).

Keywords

• bioinspired soft robotics
• buoyancy controls
• liquid–vapor phase transitions
• underwater soft-robotic platforms
• variable buoyancy systems