Title: Agile manoeuvring of dandelion-inspired micro-flyers with vortex-enabled stability Show Chinese title

Title: 具有涡旋增强稳定性的仿蒲公英微飞器的敏捷机动

Abstract: Manoeuvring untethered, centimetre-scale airborne structures has been a long-standing challenge. Active flight systems, relying on high-power-density actuators alongside mechanical and electronic components, are constrained by critical limitations in energy delivery and miniaturisation. In contrast, passive systems transported and distributed by the wind typically lack the capability for mid-air controlled manoeuvrability. Here we report an ultra-light (1.2 mg) hexagonal polymeric assembly capable of passive flight with optical control of its trajectory. This dandelion-inspired micro-flyer incorporates six radially arranged filamentous structures, of which morphology is dynamically controlled through photomechanical deformation by six independent soft actuators made of liquid crystalline elastomer thin films. Compared to the diaspore of the dandelion (Taraxacum officinale), micro-flyer demonstrate a similar terminal velocity (~0.5 m s-1), 45% better positional stability and nearly zero rotational rate (1.68 s-1; natural seeds: 50.8 s-1). Particle image velocimetry reveals that a stable asymmetric separated vortex ring underlies its flight stability, enabling mid-air steerability. When free-falling in a low-turbulent airstream, the light-driven hexapodal fliers demonstrate precise altitude control, reversible body flipping, pattern formation, interactive swarm, and controlled trajectories across three-dimensional space. The results show that responsive materials with light-induced asymmetry can bring about manoeuvrability in air, paving the way for agile, untethered controlled micro-fliers. Show Chinese abstract

Abstract: 在无系绳的情况下操控厘米级的空中结构一直是长期存在的挑战。依赖高功率密度执行器以及机械和电子组件的主动飞行系统，由于能量输送和微型化的关键限制而受到制约。相比之下，由风运输和分布的被动系统通常缺乏空中可控的机动能力。在这里，我们报告了一种超轻（1.2毫克）的六边形聚合物组装体，能够实现带有光学控制轨迹的被动飞行。这种受蒲公英启发的微飞器包含六个径向排列的丝状结构，其形态通过六个独立的由液晶弹性体薄膜制成的软执行器通过光机械变形动态控制。与蒲公英（Taraxacum officinale）的传播体相比，微飞器表现出相似的终端速度（约0.5米/秒），45%更好的位置稳定性以及几乎为零的旋转率（1.68秒-1；自然种子：50.8秒-1）。粒子图像测速技术揭示了一个稳定的非对称分离涡环是其飞行稳定性的基础，从而实现了空中可操控性。当在低湍流气流中自由下落时，光驱动的六足飞器展示了精确的高度控制、可逆的身体翻转、图案形成、交互式群体以及三维空间中的可控轨迹。结果表明，具有光诱导不对称性的响应材料可以在空气中带来机动性，为敏捷的、无系绳的可控微飞器铺平了道路。