synthetic materials that mimic the remarkable complexity of living organisms is a fundamental challenge in science and
technology. We studied the spatiotemporal patterns that emerge when an active nematic film of
microtubules and molecular motors is encapsulated within a shape-changing lipid vesicle.
Unlike in equilibrium systems, where
defects are largely static structures, in active nematics defects move spontaneously and can be described as self-propelled
particles. The combination of activity, topological constraints, and vesicle
deformability produces a myriad of dynamical states. We quantitatively
described two dynamical modes: a tunable periodic state that oscillates between
two defect configurations, and shape-changing vesicles with streaming filopodia-like protrusions. These results
demonstrate how biomimetic materials can be obtained
when topological constraints are used to control the non-equilibrium dynamics
of active matter.
reconstruction of an
active nematic vesicle. Motile defect oscillate
and tetrahedra configuration.
vesicle tension through
of four fillopodia-like