发表机构
Indian Institute of Technology (BHU); National Institute of Technology Karnataka（印度理工巴纳拉斯 Hindu 大学; 卡纳塔克国立理工学院）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究通过数值模拟探究充满活性布朗粒子的可变形闭合环的形状演化与动力学，发现系统参数可调控其形状变形、质心动力学及涌现行为，为受限活性物质研究提供了见解。
AI 中文摘要
我们数值研究了充满活性粒子的可变形闭合环的动力学。该环被建模为由被动珠粒构成的柔性边界，被动珠粒通过简谐弹簧力相互作用。环内部充满活性布朗粒子（ABPs），其活性由旋转扩散系数控制。我们通过系统改变ABPs的活性、堆积分数和环的尺寸，探究如何控制环的形状变形与动力学。在低堆积分数、低旋转扩散系数及较小环尺寸下，环因活性粒子沿边界的空间分布不均，呈现高度不规则且强烈变形的形状。提高堆积分数、旋转扩散系数或环尺寸，可促进环内活性粒子分布更均匀，从而抑制形状变形与波动，驱动环向更接近圆形的形状转变。我们进一步分析了环质心的均方位移（MSD），观察到从弹道动力学到扩散动力学的交叉现象，该交叉可通过改变系统参数进行调控。我们的结果表明，尽管环具有内部复杂性和可变形性，却展现出与单个有效活性粒子类似的涌现行为。本研究为受限活性物质的集体效应及由此产生的可变形系统宏观动力学提供了见解。
英文摘要
We numerically investigate the dynamics of a deformable closed ring filled with active particles. The ring is modeled as a flexible boundary made up of passive beads interacting with a harmonic spring force. The interior of the ring is filled with active Brownian particles (ABPs), and their activity is controlled through the rotational diffusion coefficient. We explore how, by systematically varying the activity of ABPs, packing fraction, and size of the ring, we can control the shape deformation and dynamics of the ring. At low packing fractions, low rotational diffusion coefficients, and smaller ring sizes, the ring exhibits highly irregular and strongly deformed shapes due to the uneven spatial arrangement of active particles along the boundary. Increasing the packing fraction, rotational diffusion coefficient, or ring size promotes a more even distribution of active particles within the ring, thereby suppressing shape deformations and fluctuations, driving the ring toward a more circular shape. We further analyze the mean-squared displacement (MSD) of the ring's center of mass and observe a crossover from ballistic to diffusive dynamics, which can be tuned by varying the system parameters. Our results demonstrate that, despite its internal complexity and deformability, the ring exhibits emergent behavior analogous to that of a single effective active particle. This study provides insight into the collective effects of confined active matter and the resulting macroscopic dynamics of deformable systems.
Comments13 pages, 8 figures
