Collection |

Active Matter

Active matter systems are made up of units that consume energy. Physicists group flocks of birds, molecular motors and layers of vibrating grains together in this category because they all extract energy from their surroundings at a single particle level and transform it into mechanical work. By studying the behaviours that emerge, our understanding of these systems can be enhanced and new frameworks for investigating the statistical physics of out-of-equilibrium systems can be built.

This collection brings together research and reviews from across the Nature Research journals covering key aspects of active matter with selected content from Nature Communications, Nature, Nature Physics, Nature Materials, Nature Reviews Materials and Communications Physics.

Comment and reviews

  • Nature Reviews Materials | Review Article

    The dynamics of epithelial tissues play a key role in tissue organization, both in health and disease. In this Review, the authors discuss materials and techniques for the study of epithelial movement and mechanics and investigate epithelia as active matter from a theoretical and experimental perspective.

    • Wang Xi
    • , Thuan Beng Saw
    • , Delphine Delacour
    • , Chwee Teck Lim
    •  &  Benoit Ladoux
  • Nature Communications | Review Article | open

    Active matter systems are made up of self-driven components which extract energy from their surroundings to generate mechanical work. Here the authors review the subfield of active nematics and provide a comparison between theoretical findings and the corresponding experimental realisations.

    • Amin Doostmohammadi
    • , Jordi Ignés-Mullol
    • , Julia M. Yeomans
    •  &  Francesc Sagués
  • Nature Reviews Materials | Review Article

    The field of active matter studies how internally driven motile components self-organize into large-scale dynamical states and patterns. This Review discusses how active matter concepts are important for understanding cell biology, and how the use of biochemical components enables the creation of new inherently non-equilibrium materials with unique properties that have so far been mostly restricted to living organisms.

    • Daniel Needleman
    •  &  Zvonimir Dogic
  • Nature News | News Feature

    From flocking birds to swarming molecules, physicists are seeking to understand 'active matter' — and looking for a fundamental theory of the living world.

    • Gabriel Popkin
  • Nature Physics | Progress Article

    Equilibrium physics is ill-equipped to explain all of life’s subtleties, largely because living systems are out of equilibrium. Attempts to overcome this problem have given rise to a lively field of research—and some surprising biological findings.

    • J. Prost
    • , F. Jülicher
    •  &  J-F. Joanny
  • Nature Physics | Review Article

    Evidence that ants communicate mechanically to move objects several times their size has prompted a theory that places the group near a transition between uncoordinated and coordinated motion. These findings and their implications are reviewed here.

    • Ofer Feinerman
    • , Itai Pinkoviezky
    • , Aviram Gelblum
    • , Ehud Fonio
    •  &  Nir S. Gov

Theory and Modelling

  • Nature Communications | Article | open

    Active matter describes a group of interacting units showing collective motions by constantly consuming energy from the environment, but inertia has largely been overlooked in this context. Scholz et al. show how important it can be by characterizing the dynamics of self-propelled particles in a model system.

    • Christian Scholz
    • , Soudeh Jahanshahi
    • , Anton Ldov
    •  &  Hartmut Löwen
  • Nature Communications | Article | open

    Adapting statistical physics tools to study active systems is challenging due to their non-equilibrium nature. Here the authors use simulations to present a phase diagram of a 2D active system, showing a two-step melting scenario far from equilibrium along with gas-liquid motility-induced phase separation.

    • Juliane U. Klamser
    • , Sebastian C. Kapfer
    •  &  Werner Krauth
  • Nature Communications | Article | open

    Active chiral fluids are a special case of active matter in which energy is introduced into rotational motion via local application of torque. Here Banerjee et al. develop a hydrodynamic theory of such active fluids and connect it with odd viscosity which was previously considered an abstract concept.

    • Debarghya Banerjee
    • , Anton Souslov
    • , Alexander G. Abanov
    •  &  Vincenzo Vitelli
  • Nature Communications | Article | open

    Collective self-organized behavior can be observed in a variety of systems such as colloids and microswimmers. Here O’Keeffe et al. propose a model of oscillators which move in space and tend to synchronize with neighboring oscillators and outline five types of collective self-organized states.

    • Kevin P. O’Keeffe
    • , Hyunsuk Hong
    •  &  Steven H. Strogatz
  • Nature Physics | Letter

    Ensuring topological protection of the edge states in candidate topological insulators is complicated by the need to break time-reversal symmetry. Polar active liquids present an innovative solution to this problem, as a new metamaterial design shows.

    • Anton Souslov
    • , Benjamin C. van Zuiden
    • , Denis Bartolo
    •  &  Vincenzo Vitelli

Synthetic Active Matter

  • Communications Physics | Article | open

    The “faster is slower” phenomenon expresses a decrease in average velocity of a system of objects as their individual speed increases and can be used to describe a range of scenarios from microscopic particles to sheep. The authors investigate the effects of clogging and jamming in a system of paramagnetic colloids and the relation to the faster is slower phenomenon.

    • Ralph L. Stoop
    •  &  Pietro Tierno
  • Nature Communications | Article | open

    Synthetic active particles with inter-particle propulsion have been served as a model system to study the collective animal behaviors. Here, Khadka et al. add complexity to the model by spatially controlling particle motions through a laser feedback loop in response to the collective dynamics of particles.

    • Utsab Khadka
    • , Viktor Holubec
    • , Haw Yang
    •  &  Frank Cichos
  • Nature Communications | Article | open

    Manipulation of paramagnetic microparticles can be exploited for drug delivery. Here the authors manipulate a swarm of such particles and control its shape with a magnetic field so that it can elongate reversibly, split into smaller swarms and thus be guided through a maze with multiple parallel channels.

    • Jiangfan Yu
    • , Ben Wang
    • , Xingzhou Du
    • , Qianqian Wang
    •  &  Li Zhang
  • Nature Communications | Article | open

    Bacteria communicate and organize via quorum sensing which is determined by biochemical processes. Here the authors aim to reproduce this behaviour in a system of synthetic active particles whose motion is induced by an external beam which is in turn controlled by a feedback-loop which mimics quorum sensing.

    • Tobias Bäuerle
    • , Andreas Fischer
    • , Thomas Speck
    •  &  Clemens Bechinger
  • Communications Physics | Article | open

    Motile cilia are organelles found in eukaryotic cells and serve to swim or generate surface flows. The paper presents a theoretical and experimental study showing the systematic link between synchronisation state and the beating motion of active biological filaments.

    • Armando Maestro
    • , Nicolas Bruot
    • , Jurij Kotar
    • , Nariya Uchida
    • , Ramin Golestanian
    •  &  Pietro Cicuta
  • Nature Communications | Article | open

    Active systems utilize energy input to realize structural complexity and functional diversity. This work shows that magnetic colloidal rollers spontaneously self-organize into unconfined macroscopic vortices under a magnetic field, which can be used to transport inert particles across a flat surface.

    • Gašper Kokot
    •  &  Alexey Snezhko

Biological Active Matter

  • Nature Communications | Article | open

    The study of interfaces in bacterial systems is of relevance to the spreading of bacterial colonies and pathological infections. Here the authors investigate the dynamics of active/passive interfaces in bacterial swarms and find that the boundary can be described as a propagating, diffuse elastic interface.

    • Alison E. Patteson
    • , Arvind Gopinath
    •  &  Paulo E. Arratia
  • Nature Physics | Article

    A study of how single C. elegans cells establish the polarity required for cell division reveals a general principle for pattern formation in living systems controlled by biochemical cues.

    • Peter Gross
    • , K. Vijay Kumar
    • , Nathan W. Goehring
    • , Justin S. Bois
    • , Carsten Hoege
    • , Frank Jülicher
    •  &  Stephan W. Grill
  • Nature Physics | Letter

    Single-cell tracking of up to 10,000 bacteria reveals the structure and dynamics of 3D biofilms—providing evidence to suggest that both local ordering and global biofilm architecture emerge from mechanical interactions.

    • Raimo Hartmann
    • , Praveen K. Singh
    • , Philip Pearce
    • , Rachel Mok
    • , Boya Song
    • , Francisco Díaz-Pascual
    • , Jörn Dunkel
    •  &  Knut Drescher
  • Nature Communications | Article | open

    Myosin motors drive the actin cytoskeleton out-of-equilibrium, but the role of myosin-driven active stresses in the accumulation and dissipation of mechanical work is unclear. Here, the authors synthesize an actomyosin material and find that the rate of entropy production increases non-monotonically with increasing accumulation of active stresses.

    • Daniel S. Seara
    • , Vikrant Yadav
    • , Ian Linsmeier
    • , A. Pasha Tabatabai
    • , Patrick W. Oakes
    • , S. M. Ali Tabei
    • , Shiladitya Banerjee
    •  &  Michael P. Murrell
  • Nature Communications | Article | open

    Geometrically confined suspensions of swimming bacteria can self-organize into an ordered state. Here, the authors use tiny pillars to trigger organization of bacterial motion into a stable lattice of vortices with a long-range antiferromagnetic order and control vortex direction through pillar chirality.

    • Daiki Nishiguchi
    • , Igor S Aranson
    • , Alexey Snezhko
    •  &  Andrey Sokolov
  • Nature Communications | Article | open

    Rod-shaped bacteria are an example of active matter. Here the authors find that a growing bacterial colony harbours internal cellular flows affecting orientational ordering in its interior and at the boundary. Results suggest this system may belong to a new active matter universality class.

    • D. Dell’Arciprete
    • , M. L. Blow
    • , A. T. Brown
    • , F. D. C. Farrell
    • , J. S. Lintuvuori
    • , A. F. McVey
    • , D. Marenduzzo
    •  &  W. C. K. Poon