Krüger Carsten, Bahr Christian, Herminghaus Stephan, Maass Corinna C
Max Planck Institute for Dynamics and Self-Organization (MPIDS), Am Faßberg 17, 37077, Göttingen, Germany.
Eur Phys J E Soft Matter. 2016 Jun;39(6):64. doi: 10.1140/epje/i2016-16064-y. Epub 2016 Jun 27.
The behaviour of artificial microswimmers consisting of droplets of a mesogenic oil immersed in an aqueous surfactant solution depends qualitatively on the conditions of dimensional confinement; ranging from only transient aggregates in Hele-Shaw geometries to hexagonally packed, convection-driven clusters when sedimenting in an unconfined reservoir. We study the effects of varying the swimmer velocity, the height of the reservoir, and the buoyancy of the droplet swimmers. Two simple adjustments of the experimental setting lead to a suppression of clustering: either a decrease of the reservoir height below a certain value, or a match of the densities of droplets and surrounding phase, showing that the convection is the key mechanism for the clustering behaviour.
由浸没在水性表面活性剂溶液中的介晶油滴组成的人工微游动体的行为在质量上取决于尺寸限制条件；范围从在Hele-Shaw几何形状中仅形成瞬态聚集体，到在无限制的容器中沉降时形成六边形堆积、对流驱动的簇。我们研究了改变游动体速度、容器高度和液滴游动体浮力的影响。对实验设置进行的两个简单调整可抑制聚集：要么将容器高度降低到某个值以下，要么使液滴和周围相的密度匹配，这表明对流是聚集行为的关键机制。
