  A vesicle is a spherical structure composed of a phospholipid bilayer that is
used as a container for chemicals, both it in vivo and it in vitro systems. In
both cases, the vesicles can be passively moved using external molecular motors
or flows. The active motion of the vesicles can potentially expand their
applications in microfluid devices. In this study, we created giant unilamellar
vesicles (GUVs) that loads dodecanethiol-functionalized gold nanoparticles
(AuNPs) using natural swelling method. An external alternating current (AC)
electric field was applied to the sample to drive the system. A flow was
confirmed with dense optical flow method around GUVs, even in the absence of
AuNPs. The quadratic dependence of the flow on applied elecric fields confirms
that the flow is due to induced charge electro-osmotic (ICEO) mechanism.
Furthermore, the GUVs containing AuNPs moved and deformed significantly under
external AC electric fields compared with those without AuNPs. We also
confirmed that the translational speed of GUVs was positively correlated with
the volume ratio of AuNPs. These experimental results suggest that the motion
and deformation of GUVs were cause by ICEO flow, which was unbalanced owing to
the presence of localized AuNPs on the membrane.
