title: Optimal run-and-tumble-based transportation of a Janus particle with active steering.
abstract: Although making artificial micrometric swimmers has been made possible by using various propulsion mechanisms, guiding their motion in the presence of thermal fluctuations still remains a great challenge. Such a task is essential in biological systems, which present a number of intriguing solutions that are robust against noisy environmental conditions as well as variability in individual genetic makeup. Using synthetic Janus particles driven by an electric field, we present a feedback-based particle-guiding method quite analogous to the "run-and-tumbling" behavior ofEscherichia colibut with a deterministic steering in the tumbling phase: the particle is set to the run state when its orientation vector aligns with the target, whereas the transition to the "steering" state is triggered when it exceeds a tolerance angle [Formula: see text] The active and deterministic reorientation of the particle is achieved by a characteristic rotational motion that can be switched on and off by modulating the ac frequency of the electric field, which is reported in this work. Relying on numerical simulations and analytical results, we show that this feedback algorithm can be optimized by tuning the tolerance angle [Formula: see text] The optimal resetting angle depends on signal to noise ratio in the steering state, and it is shown in the experiment. The proposed method is simple and robust for targeting, despite variability in self-propelling speeds and angular velocities of individual particles.
authors.affiliation: Department of Physics, The University of Tokyo, 113-0033 Tokyo, Japan.|Department of Chemistry, Princeton University, Princeton, NJ.
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Mano
authors.affiliation: Instituto de Física Interdisciplinar y Sistemas Complejos (IFISC), Universidad de las Islas Baleares y Consejo Superior de Investigaciones Científicas (UIB-CSIC), 07122 Palma de Mallorca, Spain jbdelfau@gmail.com.
authors.forename: Jean-Baptiste
authors.identifier: 0000-0002-2268-121X
authors.initials: JB
authors.lastname: Delfau
authors.affiliation: Department of Physics, The University of Tokyo, 113-0033 Tokyo, Japan.
authors.forename: Junichiro
authors.initials: J
authors.lastname: Iwasawa
authors.affiliation: Department of Physics, The University of Tokyo, 113-0033 Tokyo, Japan.
authors.forename: Masaki
authors.initials: M
authors.lastname: Sano
mesh_terms: D000465:Algorithms; D003198:Computer Simulation; D005246:Feedback; D053758:Nanoparticles; D036103:Nanotechnology / Q000379:methods*
keywords: Janus particles; active suspensions; feedback control; run and tumble; self-propelled particles