Hydrodynamic Instabilities, Pattern Formation and Topology in Active

活性液晶已经成为活性物质的原型，为组织有关生物过程和生物灵感材料的想法提供了一个框架，从细菌群和生长的菌落到细胞骨架。活性材料的某些共性特征，如自发流动、流体动力学不稳定性和主动湍流，已经利用液晶现象学得到了确认。这一领域继续提供非平衡物理学的基本问题，在生物学中具有潜在的广泛应用。在大多数情况下，现有的工作集中在极性或极性相，也主要是在一个二维表征。手性在自然界中普遍存在，既出现在生物结构中，也出现在构成它们的细丝和生物聚合物的悬浮液中。例如，DNA在溶液中形成手性液晶相。然而，迄今为止，还没有研究过主动应力对手性材料和结构的影响。本项目将利用手性液晶的框架和现象学来发展手性活性材料的表征和理解。我们将扩展并继续在我的小组的初步工作的基本流体动力学不稳定性，在主动胆固醇，特别是一个完整的三维分析，考虑到边界条件的影响，或限制，并研究不同的被动胆固醇纹理的稳定性。例如，确定衬底上的薄膜或活性微滴的形态是很自然的

Active liquid crystals have come to represent an archetype for active matter, offering a framework for organising ideas about biological processes and biologically inspired materials, ranging from bacterial swarms and growing colonies to the cell cytoskeleton. Certain generic traits for active materials, such as spontaneous flows, hydrodynamic instabilities and active turbulence, have been identified using the phenomenology of liquid crystals. This area continues to provide fundamental questions in non-equilibrium physics, with potentially widespread applications across biology. For the most part, existing work has focused on nematic or polar phases, and also largely on a two-dimensional characterisation. Chirality is ubiquitous in nature, appearing both in biological structures and in suspen- sions of the filaments and biopolymers that they are made from. For instance, DNA forms chiral liquid crystalline phases in solution. However, the effects of active stresses on chiral materials and structures have so far not been studied.This project will develop the characterisation and understanding of chiral active materials using the framework and phenomenology of cholesteric liquid crystals. We will extend and continue initial work in my group on the fundamental hydrodynamic instabilities in active cholesterics, in particular to a full three-dimensional analysis, to account for the influence of boundary conditions, or confinement, and to study the stability of different passive cholesteric textures. For instance, it would be natural to determine the morphology of thin films on substrates, or of active cholesteric droplets