Issue
EPL
Volume 85, Number 4, February 2009
Article Number 44001
Number of page(s) 6
Section Electromagnetism, Optics, Acoustics, Heat Transfer, Classical Mechanics, and Fluid Dynamics
DOI http://dx.doi.org/10.1209/0295-5075/85/44001
Published online 19 February 2009
EPL, 85 (2009) 44001
DOI: 10.1209/0295-5075/85/44001

Propulsion hydrodynamics of a butterfly micro-swimmer

M. Iima1 and A. S. Mikhailov2

1   Research Institute for Electronic Science, Hokkaido University - N20W10 Sapporo, 001-0020, Japan
2   Department of Physical Chemistry, Fritz Haber Institute of the Max Planck Society Faradayweg 46, 14195 Berlin, Germany, EU

makoto@nsc.es.hokudai.ac.jp

received 28 October 2008; accepted in final form 23 January 2009; published February 2009
published online 19 February 2009

Abstract
Propulsion motion of a simple mechanical model at low Reynolds numbers is considered. The model consists of two spheroids (wings) connected by a hinge. Its non-reciprocal operation cycles represent combinations of flapping motions of the wings and of their rotations, resembling conformational motions characteristic for real protein machines and similar to the propulsion pattern of a butterfly. The net generated velocity and the net stall force, exhibited by an immobilized machine on its support, are calculated and their dependence on the model parameters is discussed.

PACS
47.61.-k - Micro- and nano- scale flow phenomena.
47.15.G- - Low-Reynolds-number (creeping) flows.
87.15.H- - Dynamics of biomolecules.

© EPLA 2009