Eur. Phys. J. E (2012) 35: 71
https://doi.org/10.1140/epje/i2012-12071-4

Regular Article

Steering trajectories in magnetically actuated colloidal propellers

¹ Departament d’Estructura i Constituents de la Matèria, Universitat de Barcelona, Av. Diagonal 647, 08028, Barcelona, Spain
² Departament de Química Física, Universitat de Barcelona, Av. Diagonal 647, 08028, Barcelona, Spain
³ Institut de Nanociència i Nanotecnologia IN2UB, Universitat de Barcelona, Barcelona, Spain

^* e-mail: ptierno@ub.edu

Received: 23 March 2012
Revised: 5 June 2012
Accepted: 28 June 2012
Published online: 9 August 2012

Abstract

Microscale colloidal doublets composed of DNA-linked paramagnetic particles and floating close to a surface are able to propel in viscous fluids when subjected to external precessing magnetic fields. We show here that for certain values of the precession angle, the composite particles can be steered into tilted rather than linear trajectories characterized by a non-vanishing lateral velocity during motion. We extend the original model developed in Phys. Rev. Lett. 101, 218304 (2008) in order to explain this phenomenon, by including high-order corrections in the expansion of the director field and demonstrate the validity of this approach by comparing the analytical results with the experimental data.