Institut für Theoretische Physik II: Weiche Materie, Heinrich-Heine-Universität Düsseldorf, D-40225, Düsseldorf, Germany.
Department of Physics, University of Gothenburg, SE-41296, Gothenburg, Sweden.
Nat Commun. 2021 Oct 14;12(1):6005. doi: 10.1038/s41467-021-26319-3.
Active matter comprises self-driven units, such as bacteria and synthetic microswimmers, that can spontaneously form complex patterns and assemble into functional microdevices. These processes are possible thanks to the out-of-equilibrium nature of active-matter systems, fueled by a one-way free-energy flow from the environment into the system. Here, we take the next step in the evolution of active matter by realizing a two-way coupling between active particles and their environment, where active particles act back on the environment giving rise to the formation of superstructures. In experiments and simulations we observe that, under light-illumination, colloidal particles and their near-critical environment create mutually-coupled co-evolving structures. These structures unify in the form of active superstructures featuring a droplet shape and a colloidal engine inducing self-propulsion. We call them active droploids-a portmanteau of droplet and colloids. Our results provide a pathway to create active superstructures through environmental feedback.
活性物质由自驱动单元组成，例如细菌和合成微游泳者，它们可以自发形成复杂的模式并组装成功能微器件。这些过程之所以成为可能，是因为活性物质系统具有非平衡态的性质，其能量来源于环境向系统的单向自由能流动。在这里，我们通过实现活性粒子与其环境之间的双向耦合，在活性物质的进化中迈出了下一步，其中活性粒子对环境产生反作用，从而导致超结构的形成。在实验和模拟中，我们观察到，在光照射下，胶体粒子及其近临界环境会形成相互耦合的共同演化结构。这些结构以具有液滴形状和诱导自推进的胶体引擎的活性超结构的形式统一起来。我们称它们为活性二倍体，这是液滴和胶体的混合词。我们的结果提供了一种通过环境反馈来创建活性超结构的途径。
