Institute of Scientific Computing, Technische Universität Dresden, 01062, Dresden, Germany.
Dresden Center for Computational Materials Science (DCMS), 01062, Dresden, Germany.
Sci Rep. 2017 Jul 12;7(1):5211. doi: 10.1038/s41598-017-05612-6.
We study the spatiotemporal patterns that emerge when an active nematic film is topologically constraint. These topological constraints allow to control the non-equilibrium dynamics of the active system. We consider ellipsoidal shapes for which the resulting defects are 1/2 disclinations and analyze the relation between their location and dynamics and local geometric properties of the ellipsoid. We highlight two dynamic modes: a tunable periodic state that oscillates between two defect configurations on a spherical shape and a tunable rotating state for oblate spheroids. We further demonstrate the relation between defects and high Gaussian curvature and umbilical points and point out limits for a coarse-grained description of defects as self-propelled particles.
我们研究了当活跃的向列型膜受到拓扑约束时出现的时空模式。这些拓扑约束允许控制活跃系统的非平衡动力学。我们考虑了椭球形状，其产生的缺陷是 1/2 位错，并分析了它们的位置、动力学与椭球局部几何性质之间的关系。我们强调了两种动态模式：在球形上两个缺陷构型之间振荡的可调谐周期性状态和扁球体的可调谐旋转状态。我们进一步证明了缺陷与高高斯曲率和脐点之间的关系，并指出了将缺陷粗粒化为自行推进粒子的描述的局限性。
