Cooperative properties of thermophoretic microswimmers

热泳微型游泳器的协作特性

• 批准号: 255110239
• 负责人: Dr. Marisol Ripoll
• 金额: --
• 依托单位: Theoretische Physik der Lebenden Materie (IBI-5/IAS-2)
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2014
• 资助国家: 德国
• 起止时间: 2013-12-31 至 2020-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/255110239?language=en
• 关键词: Cooperative; properties; thermophoretic; microswimmers

Due to their similitude with biological systems and their potential practical applications, for example in lab-on-a-chip devices, synthetic microswimmers are receiving rapidly increasing attention. Self-phoretic effects have shown to be an effective and promising strategy to design such artificial microswimmers. Thermophoretic swimmers account for inhomogeneous surface heating, such that they propel due to the presence of self-generated local temperature gradients in the presence of external heating, for example by laser illumination or magnetic stimulation. The microswimmer simulation models that we have already developed and that are currently functional are microdimers, Janus colloids, and microgears. The details of the solvent interactions with the microswimmer surface determines the thermophilic or thermophobic character of the phoretic forces, and this character will be crucial to determine the microswimmer behavior, together with the particle size and shape. In this way, different microdimers have shown to hydrodynamically behave like pushers, pullers, or neutral particles; this is to generate attractive, repulsive, or neutral interparticle interactions driven by the surrounding fluid. These hydrodynamic interactions will coexist with the phoretic interactions which can have the same or different directions. The interplay of these different mechanisms, and the variety of resulting behaviors is still largely unexplored. The main purpose of this project is to investigate, by means of mesoscopic simulations the properties of solutions with multiple swimmers and of mixtures of swimmers with passive particles. This research will be performed mainly with Janus colloids, dimers, trimers, and eventually other swimmers shapes. Of particular interest are the trimers, which offer a high possible degree of asymmetry, considering the bead sizes and composition of the three beads. These might result in swimmers with a large persistent motion, different asymmetric interactions, and also moving with elliptical orbits, and with large range of chiral interactions. The investigation of the collective behavior of these swimmers will display important phenomena like clustering, swarming, and various types of synchronized motion. Some of the self-assembled structures are expected to be long-lived, under circumstances still to be identified. Examples of phenomena with important potential applications are the directed motion of phoretic swimmers, and the assembly of swimmers around a passive phoretic particle, which would enable to transport and deliver cargo to designated areas.

由于它们与生物系统的相似性及其潜在的实际应用，例如在芯片实验室设备中，合成微泳者正受到越来越多的关注。自泳效应已被证明是一种有效的和有前途的策略来设计这样的人工微泳者。热泳游泳者解释了不均匀的表面加热，使得它们在存在外部加热（例如通过激光照射或磁刺激）的情况下由于自生局部温度梯度的存在而推进。我们已经开发的目前可用的微型游泳者模拟模型是微型二聚体、Janus胶体和微型齿轮。 与microswimmer表面的溶剂相互作用的细节决定了亲合力的嗜热或疏热特性，并且该特性对于确定microswimmer行为以及颗粒尺寸和形状将是至关重要的。通过这种方式，不同的微二聚体已经显示出流体动力学行为像推进器、拉动器或中性粒子;这是为了产生由周围流体驱动的吸引力、排斥力或中性粒子间相互作用。这些流体动力学相互作用将与可以具有相同或不同方向的泳动相互作用共存。 这些不同机制的相互作用以及由此产生的各种行为在很大程度上仍未被探索。 这个项目的主要目的是调查，通过介观模拟的多个游泳者和游泳者与被动粒子的混合物的解决方案的属性。这项研究将主要与Janus胶体，二聚体，三聚体，并最终其他游泳者的形状。 特别令人感兴趣的是三聚体，考虑到三种珠粒的珠粒尺寸和组成，其提供了高度可能的不对称性。这可能会导致游泳者具有大的持续运动，不同的不对称相互作用，并且也以椭圆轨道移动，并且具有大范围的手性相互作用。 对这些游泳者集体行为的研究将显示出重要的现象，如集群、群集和各种类型的同步运动。一些自我组装的结构预计将是长期的，在情况下仍有待确定。具有重要潜在应用的现象的例子是泳动游泳者的定向运动，以及游泳者围绕被动泳动颗粒的组装，这将使得能够将货物运输和递送到指定区域。