标题： 在向列相液晶中的光激活胶体的群体感应 显示英文标题

标题： Quorum sensing of light-activated colloids in nematic liquid crystals

摘要： 运动的生物体经常探测周围环境以适应不断变化的环境。 尽管合成微泳器可以作为自推进生物体的替代物，但它们往往缺乏使生物体能够适应的复杂反馈机制。 在这项工作中，我们提出了一种实验平台，其中在向列液晶中分散的光激活胶体可以（i）根据向列锚定从定向运动切换到主动布朗运动，以及（ii）在拥挤情况下机械地调整其运动性，从而有效实现群体感应相互作用。 这两个特性是通过实验、模拟和理论揭示的独特自推进机制引起的。 我们表征了一个单独胶体的动力学，并证明如果向列锚定是垂直的，其运动由主动布朗粒子模型捕获，如果锚定是平面的，则沿向列方向进行定向自推进。 接下来，我们研究了多体动力学，表明它通过有效的群体感应相互作用经历聚类相分离。 我们的工作表明如何使用液晶和胶体的易于获取的特性来创建具有类似生命能力的适应性材料，而无需明确设计所需的机械化学反馈。 显示英文摘要

摘要： Motile living organisms routinely probe their surroundings to adapt in ever-evolving environments. Although synthetic microswimmers offer surrogates for self-propelled living entities, they often lack the complex feedback mechanisms that enable organisms to adapt. In this work, we present an experimental platform in which light-activated colloids dispersed in a nematic liquid crystal can (i) switch from directed to active Brownian motion depending on the nematic anchoring and (ii) mechanically adjust their motility in response to crowding, effectively enforcing quorum-sensing interactions. Both features are caused by a distinctive self-propulsion mechanism as unveiled through experiments, simulations, and theory. We characterize the dynamics of a single colloid and demonstrate that its motion is captured by an active Brownian particle model if the nematic anchoring is homeotropic, and by directed self-propulsion along the nematic director if the anchoring is planar. Next, we investigate the many-body dynamics, showing that it undergoes a clustering phase separation through effective quorum-sensing interactions. Our work suggests how to create adaptive materials with life-like capabilities using readily accessible properties of liquid crystals and colloids without explicitly engineering any of the needed mechano-chemical feedbacks.