Numéro |
J. Phys. II France
Volume 5, Numéro 9, September 1995
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Page(s) | 1349 - 1370 | |
DOI | https://doi.org/10.1051/jp2:1995187 |
J. Phys. II France 5 (1995) 1349-1370
Dynamics of Rayleigh-like Instability Induced by Laser Tweezers in Tubular Vesicles of Self-Assembled Membranes
R. Granek1 and Z. Olami21 Department of Materials and Interfaces, Weizmann Institute of Science, Rehovot 76100, Israel
2 Department of Chemical Physics, Weizmann Institute of Science, Rehovot 76100, Israel
(Received 31 January 1995, revised 12 May 1995, accepted 1 June 1995)
Abstract
We present a theoretical study of the Rayleigh-like, "pearling", instability recently observed in tubular vesicles of bilayer
membranes under the action of optical tweezers. The tweezers are argued to pull the membrane into their operation zone, thereby
inducing a tension in it. Consequently, the membrane can respond in a Rayleigh-like instability, in which its area decreases.
Our approach is based on a linear stability analysis of the deformations. However, because of the non-linear coupling existing
between the suction process and the growth of the unstable modes, the instability develops different characteristics. At long
times, the growth of the instability is controlled by the suction rate of the tweezers, assumed constant in time. The wavelength
of the most unstable mode is time-dependent: at short times it decreases as
; at long times it is either constant, of the order of the tube radius
R, or increases as
. The amplitude of the most unstable mode increases (at long times) as
. We delineate the different regimes under which these behaviours are predicted, and discuss their possible implications on
experiment. We also briefly discuss the possibility for other non-linear effects, such as an induced spontaneous curvature
in the membrane, which may be responsible for the appearance of very narrow tubes in the late stages.
© Les Editions de Physique 1995