School of Physics, Georgia Institute of Technology, Atlanta, GA 30318, USA.
School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA 30318, USA.
Soft Matter. 2023 Mar 8;19(10):1952-1965. doi: 10.1039/d2sm01573k.
The design of amorphous entangled systems, specifically from soft and active materials, has the potential to open exciting new classes of active, shape-shifting, and task-capable 'smart' materials. However, the global emergent mechanics that arise from the local interactions of individual particles are not well understood. In this study, we examine the emergent properties of amorphous entangled systems in an collection of u-shaped particles ("smarticles") and in living entangled aggregate of worm blobs (). In simulations, we examine how material properties change for a collective composed of smarticles as they undergo different forcing protocols. We compare three methods of controlling entanglement in the collective: external oscillations of the ensemble, sudden shape-changes of all individuals, and sustained internal oscillations of all individuals. We find that large-amplitude changes of the particle's shape using the shape-change procedure produce the largest average number of entanglements, with respect to the aspect ratio (/), thus improving the tensile strength of the collective. We demonstrate applications of these simulations by showing how the individual worm activity in a blob can be controlled through the ambient dissolved oxygen in water, leading to complex emergent properties of the living entangled collective, such as solid-like entanglement and tumbling. Our work reveals principles by which future shape-modulating, potentially soft robotic systems may dynamically alter their material properties, advancing our understanding of living entangled materials, while inspiring new classes of synthetic emergent super-materials.
无定形缠结系统的设计，特别是从软质和活性材料中设计，有可能开创出令人兴奋的新型主动、形状变化和具有任务能力的“智能”材料。然而，从单个粒子的局部相互作用中产生的全局涌现力学尚未得到很好的理解。在这项研究中，我们研究了无定形缠结系统在 U 形粒子（“smarticles”）集合和活的纠缠虫块聚集物中的涌现特性（）。在模拟中，我们研究了当 smarticles 经历不同的强制协议时，集体的材料特性如何变化。我们比较了控制集体中缠结的三种方法：集体的外部振荡、所有个体的突然形状变化以及所有个体的持续内部振荡。我们发现，使用形状变化程序进行的粒子形状的大振幅变化会产生最大的缠结平均数量（相对于纵横比（/）），从而提高集体的拉伸强度。我们通过展示在水中通过环境溶解氧如何控制虫块中单个虫的活动，展示了这些模拟的应用，从而导致纠缠的活集体出现复杂的涌现特性，例如固态缠结和翻滚。我们的工作揭示了未来形状调制、潜在的软机器人系统可能动态改变其材料特性的原则，从而增进了对纠缠材料的理解，同时激发了新的一类合成涌现超材料。
