Institut für Theoretische Physik, Technische Universität Berlin, Hardenbergstrasse 36, 10623 Berlin, Germany.
Phys Rev Lett. 2014 Mar 21;112(11):118101. doi: 10.1103/PhysRevLett.112.118101. Epub 2014 Mar 18.
We study the collective motion of confined spherical microswimmers such as active colloids which we model by so-called squirmers. To simulate hydrodynamic flow fields including thermal noise, we use the method of multiparticle collision dynamics. We demonstrate that hydrodynamic near fields acting between squirmers as well as between squirmers and bounding walls crucially determine their collective motion. In particular, with increasing density we observe a clear phase separation into a gaslike and cluster phase for neutral squirmers whereas strong pushers and pullers more gradually approach the hexagonal cluster state.
我们研究了受限的球形微泳者的集体运动,例如通过所谓的蠕动器来模拟的活性胶体。为了模拟包括热噪声在内的流体力学流场,我们使用多粒子碰撞动力学方法。我们证明了在蠕动器之间以及蠕动器与边界壁之间的流体力学近场对它们的集体运动起着至关重要的作用。特别是,随着密度的增加,我们观察到中性蠕动器明显分为气态和团簇相,而强推和强拉则逐渐接近六方团簇态。