  A photosensitive amphiphilic molecule can switch the shape of an assembled
vesicle as determined by microscopic observation. Photo-isomerization induces a
change in membrane fluctuation behavior or a morphological transition between
ellipsoid and bud shapes, depending on the asymmetrical degree of the initial
shape. The mechanism of this reversible photo-switching in the vesicle
morphology is interpreted in terms of a change in the effective cross-sectional
area of the photosensitive molecule.
