title: Topology and dynamics of active nematic vesicles.
abstract: Engineering 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 highlight 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.
authors.affiliation: Department of Physics, Technische Universität München, 85748 Garching, Germany. Institute for Advanced Study, Technische Universität München, 85748 Garching, Germany.
authors.forename: Felix C
authors.initials: FC
authors.lastname: Keber
authors.affiliation: Department of Physics, Technische Universität München, 85748 Garching, Germany.
authors.forename: Etienne
authors.initials: E
authors.lastname: Loiseau
authors.affiliation: Department of Physics, Brandeis University, Waltham, MA 02474, USA.
authors.forename: Tim
authors.initials: T
authors.lastname: Sanchez
authors.affiliation: Department of Physics, Brandeis University, Waltham, MA 02474, USA.
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: DeCamp
authors.affiliation: SISSA International School for Advanced Studies, Via Bonomea 265, 34136 Trieste, Italy. Instituut-Lorentz for Theoretical Physics, Leiden University, 2333 CA Leiden, Netherlands.
authors.forename: Luca
authors.initials: L
authors.lastname: Giomi
authors.affiliation: Physics Department and Syracuse Biomaterials Institute, Syracuse University, Syracuse, NY 13244, USA.
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Bowick
authors.affiliation: Physics Department and Syracuse Biomaterials Institute, Syracuse University, Syracuse, NY 13244, USA.
authors.forename: M Cristina
authors.initials: MC
authors.lastname: Marchetti
authors.affiliation: Institute for Advanced Study, Technische Universität München, 85748 Garching, Germany. Department of Physics, Brandeis University, Waltham, MA 02474, USA.
authors.forename: Zvonimir
authors.initials: Z
authors.lastname: Dogic
authors.affiliation: Department of Physics, Technische Universität München, 85748 Garching, Germany. abausch@mytum.de.
authors.forename: Andreas R
authors.initials: AR
authors.lastname: Bausch