writer：Ran Niu, Andreas Fisher, Thomas Palberg, Thomas Speck*
keywords：active cluster, self-propulsion
source：期刊
specific source：ACS Nano
Issue time：2018年

We present a framework to quantitatively predict the linear and rotational directed motion of

synthetic modular microswimmers. To this end, we study binary dimers and characterize their approach motion as effective interactions within a minimal model. We apply this framework to the assembly of small aggregates composed of a cationic ion-exchange particle with up to five passive particles or anionic ion-exchange particles at dilute conditions. Particles sediment and move close to a substrate, above which the ion-exchange particles generate flow. This flow mediates long-range attractions leading to a slow collapse during which long-lived clusters of a few particles assemble. The effective interactions between unlike particles break Newton’s third law. Depending on their symmetry, assemblies thus can become linear or circle swimmers, or remain inert (no directed motion). 

全文链接：https://pubs.acs.org/doi/suppl/10.1021/acsnano.8b04221