Eur. Phys. J. B 83, 391-400 (2011)
https://doi.org/10.1140/epjb/e2011-20307-7

Regular Article

Dynamics of a deformable self-propelled particle under external forcing

Department of Physics, Kyoto University, 606-8502 Kyoto, Japan

^a e-mail: takao@scphys.kyoto-u.ac.jp

Received: 21 April 2011
Received in final form: 18 August 2011
Published online: 10 October 2011

Abstract

We investigate dynamics of a deformable self-propelled particle under external fields in two dimensions based on the time-evolution equations for the center of mass and a tensor variable characterizing deformations. We consider two kinds of external force. One is a gravitational force which enters additively in the time-evolution equation for the center of mass. The other is an electric force supposing that a dipole moment is induced in the particle. This force is added to the equation for the deformation tensor. It is shown that a rich variety of dynamics appears by changing the strength of the forces and the migration velocity of a self-propelled particle. A theoretical analysis is carried out to clarify the dynamics and the bifurcations.