  In active matter systems, deformable boundaries provide a mechanism to
organize internal active stresses and perform work on the external environment.
To study a minimal model of such a system, we perform particle-based
simulations of an elastic vesicle containing a collection of polar active
filaments. The interplay between the active stress organization due to
interparticle interactions and that due to the deformability of the confinement
leads to a variety of filament spatiotemporal organizations that have not been
observed in bulk systems or under rigid confinement, including highly-aligned
rings and caps. In turn, these filament assemblies drive dramatic and tunable
transformations of the vesicle shape and its dynamics. We present simple
scaling models that reveal the mechanisms underlying these emergent behaviors
and yield design principles for engineering active materials with targeted
shape dynamics.
