Trident: A Multi-Functional Soft Appendage for Underwater Locomotion and Grasping

Soft underwater robots, designed to mimic the movement and adaptability of aquatic animals, use flexible materials like silicone and rubber to change shape and navigate complex environments. These robots can squeeze through narrow spaces and avoid obstacles, making them ideal for exploring underwater caves, coral reefs, and shipwrecks without harming marine life. Their embodied intelligence integrates sensing, actuation, and control, allowing adaptive responses to environmental stimuli and enabling complex tasks with minimal external control. In this letter, we introduce <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Trident</i>, a novel hybrid soft-rigid robot developed by connecting three soft modules with integrated tendons. This multi-functional robot is capable of both swimming and grasping underwater objects. The robot's design and fabrication processes are detailed, alongside experimental analyses of its performance. This innovative design combines the flexibility of soft materials and the strength of rigid structures, providing a versatile solution for underwater exploration, environmental monitoring, and marine research.