Propulsion and Interaction of Hot Brownian Swimmers

自体潜热(热)微泳者是一种多才多艺的典型的活性粒子，由粒子表面和附近基质的加热所激发的热渗透流驱动。它们有趣的非平衡布朗涨落在理论和实验上都得到了很好的控制。我们支持非平衡分子动力学模拟的高度优化的并行数值程序建立了一个连接实验和理论的独立平台。基于前一期资助的结果，我们将结合实验、模拟和理论来进一步阐明游泳者之间的相互作用以及与基质表面的相互作用。我们将继续使用创新的光子轻推技术来实现对热泳者的无力和无扭矩操纵和操纵，并将其扩展到允许对成群的热泳者的游泳压力和表面张力进行实验控制测量。理论上，我们将推广我们最近在所谓的活性布朗粒子(ABP)相互作用组件的系统粗粒化方面的进展，我们可以明确地推导出所谓的游泳压力和表面张力的形式表达式。我们将把这一分析扩展到动量守恒的(湿)微观模型，用速度而不是经典的(干)ABP游泳力来表示游泳。最终，我们的目标是包含我们的模拟和实验揭示的特定于游泳者的交互作用。在一个更实用的方向上，通过专门定制的人工交互来扩展或取代我们热泳者之间的物理交互将是有趣的。我们计划通过光子轻推实现反馈控制，作为游泳者通过(延迟的)信息交换进行互动的机制。它们将适合于模拟生命系统中信息触发的蜂群效应。从长远来看，这应该会把我们的热泳者模型系统变成一个多功能的实验实验室，来模拟通用的活性物质系统。

Self-thermophoretic (hot) microswimmers are versatile and prototypical active particles driven by thermo-osmotic flows excited by heating at the particle surface and nearby substrates. Their interesting nonequilibrium Brownian fluctuations are theoretically and experimentally well under control. Our highly optimised parallel numerical code for supporting nonequilibrium molecular dynamics simulations establishes an independent platform to link experiment and theory. Based on the results of the preceding funding period, we will concert experiments, simulations, and theory to further elucidate the mutual interactions of swimmers and interactions with substrate surfaces. We will continue to employ the innovative technique of photon nudging for a force-free and torque-free manipulation and steering of hot swimmers, and extend it to allow for controlled measurements of the swim pressure and surface tension of flocks of hot swimmers experimentally. Theoretically, we will extend our recent progress in the systematic coarse-graining of interacting assemblies of so-called active-Brownian-particles (ABP), for which we could unambiguously derive formal expressions for the so-called swim pressure and the surface tension. We will extend this analysis to a (wet) microscopic model with momentum conservation, representing swimming by a velocity rather than by the classical (dry) ABP swim force. Eventually, we aim at an inclusion of the swimmer-specific interactions revealed by our simulations and experiments. In a more applied direction, it will be interesting to extend or supersede the physical interactions between our hot swimmers by specifically tailored artificial interactions. We plan to implement a feedback control via photon nudging as a mechanism for swimmers to mutually interact via an exchange of (delayed) information. These will be suitable to mimic the effect of information-triggered flocking in living systems. In the long run, this should turn our model system of hot swimmers into a versatile experimental laboratory to emulate generic active matter systems.