The propulsion mechanisms and collective dynamics of chemically powered Janus sphere dimers at the micro- and nanoscales, confined in a quasi-two-dimensional geometry, are investigated using a coarse-grained microscopic dynamical model. These active Janus dimers consist of two identical Janus spheres, featuring a catalytic cap on one hemisphere. The chemical reaction taking place on the catalytic surface generates asymmetric concentration gradients of product molecules around the Janus sphere, leading to the self-propulsion of the dimers. Depending on the dimer configuration, they exhibit various motion behaviors such as forward propulsion, rotation, and restricted stochastic motion. Due to chemotactic effects and self-diffusiophoretic forces, ensembles of dimers spontaneously form diverse structures, such as transient clusters, stable rotational ensembles, and antiparallel aligned doublets. This study demonstrates that the configurations of Janus sphere dimers significantly influence their self-propulsion and collective behaviors, providing crucial insights for the design and control of active micro- and nanoscale systems.

中文翻译：

---

化学推进的 Janus 球二聚体在复杂溶剂中的动力学和集体行为。


使用粗粒微观动力学模型研究了化学动力 Janus 球二聚体在微观和纳米尺度上的推进机制和集体动力学，这些二聚体被限制在准二维几何结构中。这些活性 Janus 二聚体由两个相同的 Janus 球体组成，在一个半球上具有催化帽。催化表面上发生的化学反应在 Janus 球周围产生不对称的产物分子浓度梯度，导致二聚体的自推进。根据二聚体配置，它们表现出各种运动行为，例如向前推进、旋转和受限随机运动。由于趋化效应和自扩散作用力，二聚体的集合自发形成不同的结构，例如瞬时簇、稳定的旋转集合和反平行对齐的双峰。这项研究表明，Janus 球二聚体的构型显着影响它们的自我推进和集体行为，为有源微纳米级系统的设计和控制提供了重要的见解。