Inspired by the snap-through action of a steel hairclip, we propose a design method for in-plane prestressed mechanisms that exhibit biomimetic morphing and high locomotion performance. Compliant bistable flapping mechanisms are fabricated using this method and are mounted on our untethered soft robotic fish. Using this mechanism, we achieve life-like undulation with a Strouhal number (1) of St = 0.28 and a velocity of 2.03 body lengths per second (43.6 cm/s), a three-fold improvement over past compliant fish robots. A tethered pneumatic version indicates that this mechanism is compatible with soft actuators. We study the mechanism both computationally and experimentally and suggest that elastic instability may offer a path to overcome the speed challenge of soft and compliant robots.

翻译：受钢制发夹的快速弹跳动作启发，我们提出了一种面内预应力机构的设计方法，该机构具有仿生变形能力与高运动性能。利用该方法制造了符合双稳态扑动机构，并将其安装于无缆软体机器鱼上。通过该机构，我们实现了斯特劳哈尔数(1)为St=0.28、速度达2.03倍体长/秒(43.6厘米/秒)的仿生波动运动，其性能较以往的柔顺机器鱼提升三倍。一种带缆气动版本表明该机构与软体执行器兼容。我们通过计算与实验方法研究了该机构，并指出弹性失稳可能为克服软体与柔顺机器人速度挑战提供新路径。