Assembly structures and dynamics of active colloidal cells
Assembly structures and dynamics of active colloidal cells
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活性胶体细胞的组装结构和动力学
DOI：
10.1039/c9sm00619b
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发表时间：
2019
期刊：
影响因子：
3.4
通讯作者：
Chen Kang
中科院分区：
文献类型：
--
作者：
Shan Wen jie;Zhang Fei;Tian Wen de;Chen Kang
许多类型的活性物质都是可变形的，例如上皮细胞和细菌。为了模拟可变形的特征，我们建立了一个称为活性胶体细胞（ACC）的模型，即一个被自推进粒子（SPP）包围的囊泡，它作为一个整体可以主动移动。基于该模型，我们通过 Langevin 动力学模拟研究了变形能力在 ACC 的装配结构和动力学中的作用。我们发现可变形性削弱了自捕获效应，从而抑制了可变形软 ACC（sACC）的聚类和相分离。 sACC 不像普通 SPP 那样形成一个大而紧凑的簇，而是在相分离区域堆积成松散的网络或多孔结构。凝聚相呈液体状，其中sACC被强烈压缩和变形，但仍保持较高的运动性。气体与凝聚相之间的界面模糊且不稳定，有效界面能很低。我们的工作为可变形性在活性物质组装中的作用提供了新的见解，也为进一步研究不同类型可变形活性物质提供了参考。
Many types of active matter are deformable, such as epithelial cells and bacteria. To mimic the feature of deformability, we built a model called an active colloidal cell (ACC), i.e. a vesicle enclosed with self-propelled particles (SPPs), which as a whole can move actively. Based on the model, we then study the role of deformability in the assembly structures and dynamics of ACCs by Langevin dynamics simulation. We find that deformability weakens the self-trapping effect and hence suppresses the clustering and phase separation of the deformable soft ACCs (sACCs). Instead of forming a large compact cluster like ordinary SPPs, sACCs pack into a loose network or porous structure in the phase-separation region. The condensed phase is liquid-like, in which sACCs are strongly compressed and deformed but still keep high motility. The interface between the gas and the condensed phases is blurry and unstable, and the effective interfacial energy is very low. Our work gives new insights into the role of deformability in the assembly of active matter and also provides a reference for further studies on different types of deformable active matter.