Description: Confirmations, hydrodynamic interactions, and instabilities of sedimenting semiflexible filaments

This title appears in the Scientific Report : 2015

Confirmations, hydrodynamic interactions, and instabilities of sedimenting semiflexible filaments

The conformations and dynamics of semiflexible filaments subject to a homogeneous external (gravitational) field, e.g., in a centrifuge, are studied numerically and analytically. The competition between hydrodynamic drag and bending elasticity generates new shapes and dynamical features. We show tha...

Personal Name(s):	Saggiorato, Guglielmo
	Elgeti, Jens / Winkler, Roland G. / Gompper, Gerhard
Contributing Institute:	Theorie der Weichen Materie und Biophysik; IAS-2 Theorie der Weichen Materie und Biophysik; ICS-2
Published in:	Soft matter, 11 (2015) 37, S. 7337 - 7344
Imprint:	London Royal Soc. of Chemistry 2015
DOI:	10.1039/C5SM01069A
PubMed ID:	26270609
Document Type:	Journal Article
Research Program:	Physical Basis of Diseases
Link:	OpenAccess OpenAccess
	Publikationsportal JuSER

Please use the identifier: http://dx.doi.org/10.1039/C5SM01069A in citations.
Please use the identifier: http://hdl.handle.net/2128/22830 in citations.

The conformations and dynamics of semiflexible filaments subject to a homogeneous external (gravitational) field, e.g., in a centrifuge, are studied numerically and analytically. The competition between hydrodynamic drag and bending elasticity generates new shapes and dynamical features. We show that the shape of a semiflexible filament undergoes instabilities as the external field increases. We identify two transitions that correspond to the excitation of higher bending modes. In particular, for strong fields the filament stabilizes in a non-planar shape, resulting in a sideways drift or in helical trajectories. For two interacting filaments, we find the same transitions, with the important consequence that the new non-planar shapes have an effective hydrodynamic repulsion, in contrast to the planar shapes which attract themselves even when their osculating planes are rotated with respect to each other. For the case of planar filaments, we show analytically and numerically that the relative velocity is not necessarily due to a different drag of the individual filaments, but to the hydrodynamic interactions induced by their shape asymmetry.