Synchronized oscillations, traveling waves, and jammed clusters induced by steric interactions in active filament arrays
Synchronized oscillations, traveling waves, and jammed clusters induced by steric interactions in active filament arrays
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DOI：
10.1039/d0sm01162b
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发表时间：
2021-01-28
期刊：
影响因子：
3.4
通讯作者：
Gopinath, Arvind
中科院分区：
文献类型：
--
作者：
Chelakkot, Raghunath;Hagan, Michael F.;Gopinath, Arvind
自主活跃的弹性丝彼此相互作用以实现合作和同步，是生物学中许多关键功能的基础。这种集体反应的机制和稳定同步的基本要素仍然是个谜。受这些生物实体如何将弹性与分子运动活动相结合以产生持续振荡的启发，已经开发了许多合成活性丝系统来模仿这些生物活性丝的振荡。在这里，我们描述了在空间相互作用可能影响或主导集体动力学的条件下，这种仿生多丝阵列中出现的集体动力学和稳定的时空模式。为了关注空间相互作用的作用，我们使用布朗动力学研究系统，而不考虑长程流体动力学相互作用。模拟将每根细丝视为一条连接的自推进胶体链。我们证明，即使在没有丝间流体动力学相互作用的情况下，短程空间位阻丝间相互作用和丝粗糙度也足以产生丰富多样的集体时空振荡、行进和静态模式。我们首先分析了两丝和三丝簇的集体动力学，并确定了空间相互作用导致同步振荡和强闭塞态的参数范围。将这些结果推广到大型一维阵列，我们发现了丰富的涌现行为，包括行进的异时波和由阵列几何形状、细丝活动和细丝弹性之间的相互作用控制的调制波列。有趣的是，异时波的存在对于丝间间距来说是非单调的。我们还发现，细丝粗糙度显着影响动力学 - 具体而言，细丝粗糙度会产生锁定机制，将行波图案转换为静态卡住和卡住的配置。综上所述，模拟表明，短程空间位阻丝间相互作用可以与互补的流体动力学相互作用相结合，以控制振荡集体模式的发展和调节。此外，粗糙度和空间相互作用可能对于堵塞空间周期态的发展至关重要。在纯流体动力学相互作用的系统中未观察到的时空特征。
Autonomous active, elastic filaments that interact with each other to achieve cooperation and synchrony underlie many critical functions in biology. The mechanisms underlying this collective response and the essential ingredients for stable synchronization remain a mystery. Inspired by how these biological entities integrate elasticity with molecular motor activity to generate sustained oscillations, a number of synthetic active filament systems have been developed that mimic oscillations of these biological active filaments. Here, we describe the collective dynamics and stable spatiotemporal patterns that emerge in such biomimetic multi-filament arrays, under conditions where steric interactions may impact or dominate the collective dynamics. To focus on the role of steric interactions, we study the system using Brownian dynamics, without considering long-ranged hydrodynamic interactions. The simulations treat each filament as a connected chain of self-propelling colloids. We demonstrate that short-range steric inter-filament interactions and filament roughness are sufficient - even in the absence of inter-filament hydrodynamic interactions - to generate a rich variety of collective spatiotemporal oscillatory, traveling and static patterns. We first analyze the collective dynamics of two- and three-filament clusters and identify parameter ranges in which steric interactions lead to synchronized oscillations and strongly occluded states. Generalizing these results to large one-dimensional arrays, we find rich emergent behaviors, including traveling metachronal waves, and modulated wavetrains that are controlled by the interplay between the array geometry, filament activity, and filament elasticity. Interestingly, the existence of metachronal waves is non-monotonic with respect to the inter-filament spacing. We also find that the degree of filament roughness significantly affects the dynamics - specifically, filament roughness generates a locking-mechanism that transforms traveling wave patterns into statically stuck and jammed configurations. Taken together, simulations suggest that short-ranged steric inter-filament interactions could combine with complementary hydrodynamic interactions to control the development and regulation of oscillatory collective patterns. Furthermore, roughness and steric interactions may be critical to the development of jammed spatially periodic states; a spatiotemporal feature not observed in purely hydrodynamically interacting systems.