Gordei Anchutkin

Abstract Self-propelled microparticles create flow fields that determine how they interact with surfaces, external flows, and each other. These flow fields fall into distinct classes–pushers, pullers, and neutral swimmers–each exhibiting fundamentally different collective behaviors. In all existing synthetic systems, this hydrodynamic character is permanently set during fabrication. Here we demonstrate that the hydrodynamic identity of microswimmers can be programmed and switched on demand.

A hallmark of bacteria is their so-called “run-and-tumble” motion and its variants, consisting of a sequence of linear directed “runs” and distinct rotation events that constantly alternate due to biochemical feedback. It plays a crucial role in the ability of bacteria to move through chemical gradients and has inspired a fundamental active particle model. Nevertheless, synthetic active particles generally do not exhibit run-and-tumble motion but rather active Brownian motion.