Volume 85, Number 3, February 2009
Article Number 38002
Number of page(s) 6
Section Interdisciplinary Physics and Related Areas of Science and Technology
Published online 06 February 2009
EPL, 85 (2009) 38002
DOI: 10.1209/0295-5075/85/38002

Self-propelled rods near surfaces

J. Elgeti and G. Gompper

Institut für Festkörperforschung, Forschungszentrum Jülich - D-52425 Jülich, Germany, EU

received 7 December 2008; accepted in final form 9 January 2009; published February 2009
published online 6 February 2009

We study the behavior of self-propelled nano- and micro-rods in three dimensions, confined between two parallel walls, by simulations and scaling arguments. Our simulations include thermal fluctuations and hydrodynamic interactions, which are both relevant for the dynamical behavior at nano- to micro-meter length scales. In order to investigate the importance of hydrodynamic interactions, we also perform Brownian-dynamics$\hbox{--} $like simulations. In both cases, we find that self-propelled rods display a strong surface excess in confined geometries. An analogy with semi-flexible polymers is employed to derive scaling laws for the dependence on the wall distance, the rod length, and the propulsive force. The simulation data confirm the scaling predictions.

82.70.-y - Disperse systems; complex fluids.
45.50.-j - Dynamics and kinematics of a particle and a system of particles.
05.40.-a - Fluctuation phenomena, random processes, noise, and Brownian motion.

© EPLA 2009