2024/02/07 by Gordei Anchutkin, Anchutkin, Gordei, Viktor Holubec +3 · 3 citations
Engineering · Physics and Astronomy · #Experimental and Theoretical Physics Studies #FOS: Physical sciences #Micro and Nano Robotics #Robotic Locomotion and Control #Soft Condensed Matter (cond-mat.soft)
paper · pdf · doi:10.48550/arxiv.2402.04697
openalex publication_date 2024/02/07 · openalex created_date 2024/02/09 · openalex updated_date 2026/07/28
A hallmark of bacteria is their so-called "run-and-tumble" motion, consisting of a sequence of linear directed "runs" and random rotations that constantly alternate due to biochemical feedback. It plays a crucial role in the ability of bacteria to move through chemical gradients and inspired a fundamental active particle model. Nevertheless, synthetic active particles generally do not exhibit run-and-tumble motion but rather active Brownian motion. We show in experiments that ellipsoidal thermophoretic Janus particles, propelling along their short axis, can yield run-and-tumble-like motion even without feedback. Their hydrodynamic wall interactions under strong confinement give rise to an effective double-well potential for the declination of the short axis. The geometry-induced timescale separation of the in-plane rotational dynamics and noise-induced transitions in the potential then yields run-and-tumble-like motion.