Biological systems often involve the self-assembly of basic components into complex and function- ing structures. Artificial systems that mimic such processes can provide a well-controlled setting to explore the principles involved and also synthesize useful micromachines. Our experiments show that immotile, but active, components self-assemble into two types of structure that exhibit the fundamental forms of motility: translation and rotation. Specifically, micron-scale metallic rods are designed to induce extensile surface flows in the presence of a chemical fuel; these rods interact with each other and pair up to form either a swimmer or a rotor. Such pairs can transition reversibly be- tween these two configurations, leading to kinetics reminiscent of bacterial run-and-tumble motion.
@article{arxiv.1509.06330,
title = {Dynamic self-assembly of microscale rotors and swimmers},
author = {Megan S. Davies Wykes and Jeremie Palacci and Takuji Adachi and Leif Ristroph and Xiao Zhong and Michael D. Ward and Jun Zhang and Michael J. Shelley},
journal= {arXiv preprint arXiv:1509.06330},
year = {2017}
}