The Rudolf Peierls Centre for Theoretical Physics, 1 Keble Road, Oxford, OX1 3NP, UK.
Soft Matter. 2017 May 31;13(21):3853-3862. doi: 10.1039/c6sm02310j.
The spontaneous emergence of collective flows is a generic property of active fluids and often leads to chaotic flow patterns characterised by swirls, jets, and topological disclinations in their orientation field. However, the ability to achieve structured flows and ordered disclinations is of particular importance in the design and control of active systems. By confining an active nematic fluid within a channel, we find a regular motion of disclinations, in conjunction with a well defined and dynamic vortex lattice. As pairs of moving disclinations travel through the channel, they continually exchange partners producing a dynamic ordered state, reminiscent of Ceilidh dancing. We anticipate that this biomimetic ability to self-assemble organised topological disclinations and dynamically structured flow fields in engineered geometries will pave the road towards establishing new active topological microfluidic devices.
集体流动的自发出现是活性流体的通用特性，通常会导致混沌的流动模式，其特点是在其取向场中出现漩涡、射流和拓扑缺陷。然而，在活性系统的设计和控制中，实现结构化流动和有序缺陷具有特别重要的意义。通过将活性向列流体限制在通道内，我们发现了缺陷的规则运动，同时还发现了明确的动态涡旋晶格。当移动的缺陷对穿过通道时，它们会不断地交换伴侣，产生动态有序的状态，让人联想到 Ceilidh 舞蹈。我们预计，这种仿生能力能够在工程几何形状中自组装有序的拓扑缺陷和动态结构化流场，将为建立新的活性拓扑微流控装置铺平道路。
