Abstract
With the rapid advancement of soft robotics and bio-inspired anatomy, small-scale underwater robots have achieved significant improvements in swimming and locomotion performance. Nevertheless, achieving a fully compact and wireless aquatic robot capable of long-term operation and adaptive control in dynamic underwater environments remain a major challenge for artificial platforms. This paper presents a cyborg crayfish (Cherax quadricarinatus), representing a soft biohybrid robotic approach with potential for wireless underwater locomotion control. Through electrical stimulation, two controllable behaviours: underwater turning and tail-flick triggering are achieved. Experimental results demonstrate consistent turning responses and backward propulsion via tail-flick triggering, both activated by electrical stimulation. Furthermore, a graded correlation between stimulation duration and motion magnitude is observed, providing a basis for future control strategies. These findings establish a foundational framework for self-actuating and naturally adaptive aquatic biohybrid robots, eliminating the need for complex design and fabrication processes required for small-scale underwater systems.