发表机构
Indian Institute of Technology Bombay; Indian Institute of Technology Ropar（印度理工学院孟买分校; 印度理工学院罗帕尔分校）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
该研究发现形状依赖的流体动力学相互作用会影响自推进泳动体的对齐，通过实验和反应-扩散模型揭示了其有序-无序转变规律，或对生物集群有重要意义。
AI 中文摘要
集群行为源于活性自推进物体集合中相邻个体间的动力学对齐。然而，作为中间介质的流体通常仅被视为动量汇，对对齐过程并不重要，因此集群系统被描述为动量不守恒的“干”活性物质。本文研究受限的自推进马兰戈尼泳动体系统，其中流体介质的反馈（关键取决于泳动体的形状）会影响其对齐行为。我们使用多达30个部分涂有樟脑的三角纸船作为极性泳动体，发现随樟脑浓度和泳动体密度变化，系统会出现无序到有序的转变，以及不寻常的重入有序到无序转变。我们通过构建樟脑场的反应-扩散模型（与泳动体动力学耦合）重现了这些转变，其中推进力源于表面张力梯度。本文讨论的形状依赖流体动力学相互作用，对生物有机体中高效集群也可能至关重要。
英文摘要
Flocking results from dynamical alignment among neighbors in a collection of active self-propelling objects. The intervening medium, typically a fluid, however, is not considered to be important for alignment, except for acting as a momentum sink. The flocking system is therefore described as momentum nonconserving "dry" active matter. Here we investigate a confined system of self-propelled Marangoni swimmers where feedback from the fluid medium, which crucially depends on the shape of the swimmers, influences their alignment. Using up to thirty partially camphor-coated triangular paper boats as polar swimmers, we uncover a disorder-to-order transition, and an unusual re-entrant order-to-disorder transition, as functions of camphor concentration and swimmer density, respectively. We reproduce these transitions by formulating a reaction-diffusion model for the camphor field, coupled to the swimmer dynamics, where propulsion forces arise from surface tension gradients. The shape-dependent hydrodynamic interaction discussed here could be central to efficient flocking in living organisms too.
