Chen Zhihan, Ding Hongru, Kollipara Pavana Siddhartha, Li Jingang, Zheng Yuebing
Materials Science and Engineering Program and Texas Materials Institute, The University of Texas at Austin, Austin, TX, 78712, USA.
Walker Department of Mechanical Engineering, The University of Texas at Austin, Austin, TX, 78712, USA.
Adv Mater. 2024 Feb;36(7):e2304759. doi: 10.1002/adma.202304759. Epub 2023 Dec 4.
The collective motion observed in living active matter, such as fish schools and bird flocks, is characterized by its dynamic and complex nature, involving various moving states and transitions. By tailoring physical interactions or incorporating information exchange capabilities, inanimate active particles can exhibit similar behavior. However, the lack of synchronous and arbitrary control over individual particles hinders their use as a test system for the study of more intricate collective motions in living species. Herein, a novel optical feedback control system that enables the mimicry of collective motion observed in living objects using active particles is proposed. This system allows for the experimental investigation of the velocity alignment, a seminal model of collective motion (known as the Vicsek model), in a microscale perturbed environment with controllable and realistic conditions. The spontaneous formation of different moving states and dynamic transitions between these states is observed. Additionally, the high robustness of the active-particle group at the critical density under the influence of different perturbations is quantitatively validated. These findings support the effectiveness of velocity alignment in real perturbed environments, thereby providing a versatile platform for fundamental studies on collective motion and the development of innovative swarm microrobotics.
在诸如鱼群和鸟群等有生命的活性物质中观察到的集体运动，其特点是具有动态和复杂的性质，涉及各种运动状态和转变。通过调整物理相互作用或引入信息交换能力，无生命的活性粒子可以表现出类似的行为。然而，对单个粒子缺乏同步和任意控制阻碍了它们作为研究生物物种中更复杂集体运动的测试系统的应用。在此，提出了一种新颖的光学反馈控制系统，该系统能够使用活性粒子模拟在生物物体中观察到的集体运动。该系统允许在具有可控和现实条件的微观尺度扰动环境中，对集体运动的一个开创性模型（称为Vicsek模型）的速度对齐进行实验研究。观察到不同运动状态的自发形成以及这些状态之间的动态转变。此外，还定量验证了活性粒子群在不同扰动影响下在临界密度时的高鲁棒性。这些发现支持了速度对齐在实际扰动环境中的有效性，从而为集体运动的基础研究和创新群体微机器人的发展提供了一个通用平台。
