Center for Soft Condensed Matter Physics and Interdisciplinary Research, School of Physical Science and Technology, Soochow University, Suzhou 215006, People's Republic of China.
J Chem Phys. 2019 Jan 28;150(4):044907. doi: 10.1063/1.5078694.
Langevin dynamics simulations are employed to study the shape transformation of a two-dimensional vesicle induced by active particles both inside and outside. We find that the shape of the vesicle changes from circle, to capsule, and eventually to dumbbell with the enhancement of the particle activity. Under the cooperation between the inside and the outside active particles, such significant shape transformation is realized by tuning the activity in a small range. And unexpectedly, the fluctuations of the capsule and the dumbbell shapes are not completely random but mostly along the direction of the short axis. In the situation of strong activity, the inside of the dumbbell vesicle is analogous to a system of two chambers, which are connected by a narrow channel. Intriguingly, we observe the vibration of the channel width, accompanied with the exchange of active particles between the two chambers. We also find that dynamical manipulation of the vesicle shape is possible through tuning the particle activity dynamically. This work provides new ideas to the control of the vesicle morphology and new insights into the dynamics in the vesicle's shape transformation.
我们运用朗之万动力学模拟研究了内外两侧活性粒子诱导的二维囊泡的形状转变。我们发现，随着粒子活性的增强，囊泡的形状从圆形变为胶囊形，最终变为哑铃形。在内外两侧活性粒子的协同作用下，通过在小范围内调节活性，可以实现这种显著的形状转变。出乎意料的是，胶囊和哑铃形状的波动并不是完全随机的，而是大多沿着短轴的方向。在活性较强的情况下，哑铃状囊泡的内部类似于两个腔室的系统，它们通过一个狭窄的通道连接。有趣的是，我们观察到了通道宽度的振动，伴随着两个腔室之间活性粒子的交换。我们还发现，通过动态调节粒子活性，可以实现对囊泡形状的动力学控制。这项工作为囊泡形态的控制提供了新的思路，并深入了解了囊泡形状转变中的动力学。
