Underwater robotics has advanced significantly over recent decades. however, the development of miniaturized underwater robots remains limited by low energy densities of traditional power sources. Nature offers compelling solutions-organisms like mantis shrimps and fleas utilize latch-mediated spring actuation (LaMSA) systems that achieve rapid movements through a decoupled energy storage and release mechanism. Despite extensive studies of LaMSA, replicating such rapid, asymmetric actuation within simple, compact structures remains challenging. In this work, we introduce a bioinspired, soft bistable actuator with an integrated latch mechanism that enables asymmetric energy input and release using a single motor. Coupled with fin structures, this design facilitates efficient underwater propulsion and maneuverability. Experimental results demonstrate stable periodic flapping, precise steering, and a maximum thrust of 0.528 N, impulse of 0.147 Ns, and vertical displacement of 30 mm. By modulating fin angles, the robot achieves versatile motions, including vertical ascent, diagonal forward movement, and lateral translation. This study presents a novel, energy-efficient approach for controlling motion in compact underwater robots, paving the way for advanced biomimetic designs with potential applications in exploration, environmental monitoring, and inspection.

翻译：近年来，水下机器人技术取得了显著进展。然而，由于传统能源能量密度较低，微型化水下机器人的发展仍受到限制。自然界提供了引人注目的解决方案——诸如螳螂虾和跳蚤等生物利用闩锁介导的弹簧驱动（LaMSA）系统，通过解耦的能量储存与释放机制实现快速运动。尽管LaMSA已被广泛研究，但在简单紧凑的结构中复制这种快速非对称驱动仍具挑战性。本文提出了一种仿生软体双稳态驱动器，其集成了闩锁机构，可通过单个电机实现非对称的能量输入与释放。结合鳍状结构，该设计实现了高效的水下推进与机动性。实验结果表明，该机器人能稳定周期性拍动、精确转向，并达到最大推力0.528 N、冲量0.147 N·s以及30 mm的垂直位移。通过调节鳍角，机器人可实现垂直上升、斜向前进和横向平移等多种运动模式。本研究为紧凑型水下机器人的运动控制提供了一种新颖的节能方案，为具有勘探、环境监测和检测等潜在应用的高级仿生设计铺平了道路。