Artificial Muscles for Underwater Soft Robots: Materials and Their Interactions

Underwater soft robots are typically constructed from soft and flexible materials, which enable them to adapt to aquatic environments where the terrain can be complex. They are often inspired by soft-bodied aquatic animals and can be used for a range of tasks, such as underwater exploration, environmental monitoring, and rescue operations. However, the design of these robots presents significant challenges, as it requires soft materials and systems that can withstand the harsh and varied conditions of ocean environments. This review delves into the physics of soft materials and outlines the constitutive models for such materials. Through an exploration of the muscle structures in aquatic creatures like octopuses and stingrays, we highlight the interplay between the materials that make up artificial muscles and how these muscles interact with their external surroundings. Finally, we conclude by outlining unresolved challenges and providing potential avenues for future research.