21 research outputs found
Motion of a massive microsphere bound to a spherical vesicle
We study the motion of a small solid particle (a few micrometers in size) attached
to the membrane of a spherical giant lipid vesicle. By means of optical manipulation, the particle
is first brought near the top of the vesicle, and released. We determine the friction experienced
by the particle moving along the vesicle surface under the action of gravity. From experiments
with latex and glass beads, we check that SOPC membranes are fluid at room temperature
(static shear modulus u = 0) and estimate the shear viscosity of SOPC bilayers: nm = 3 * 10^(-6)
surface poise
Motion of a massive microsphere bound to a spherical vesicle
We study the motion of a small solid particle (a few micrometers in size)
attached to the membrane of a spherical giant lipid vesicle. By means of
optical manipulation, the particle is first brought near the top of the vesicle,
and released. We determine the friction experienced by the particle moving
along the vesicle surface under the action of gravity. From experiments with
latex and glass beads, we check that SOPC membranes are fluid at room temperature
(static shear modulus ) and estimate the shear viscosity of SOPC bilayers:
surface poise
Falling ball viscosimetry of giant vesicle membranes: Finite-size effects
We study the general problem of the
friction felt by a spherical solid particle which moves parallel to
the membrane of a spherical vesicle. Experiments are carried out
with SOPC vesicles at room temperature, with different particle and
vesicle sizes. Experimental data show considerable finite-size effects
whenever the particle is not very small compared to the vesicle. These
effects are found consistent with the hydrodynamical theory of the
vesicle-particle problem. This agreement allows for a "robust"
determination of membrane viscosity, independently of particle and
vesicle sizes