Self-aligning polar active matter

Reviews of Modern Physics, vol. 97

Abstract

What if active units could align--or even antialign--their orientation with their own velocity? This intriguing self-alignment property unlocks a spectrum of fascinating behaviors, from single self-propelled particles orbiting in harmonic traps to transformative collective phenomena like synchronized motion in dense or solid elastic assemblies. Unlike systems where units simply mimic their neighbors, self-alignment fundamentally reshapes how motion emerges, paving the way for groundbreaking discoveries in biology, smart materials, and robotics. This review uncovers the hidden power of self-alignment in active systems, introduces a unified mathematical and conceptual framework, explores existing models of self-alignment, and highlights its transformative impact on the study and real-world applications of active systems.

Authors 7

1. Paul Baconnier Aachen

   Leiden University · Université Paris Sciences et Lettres · Institute for Atomic and Molecular Physics

   Affiliation as printed

   AMOLF

   Leiden University

   Lorentz Institute

   PSL Research University

2. Olivier Dauchot

   Université Paris Sciences et Lettres

   Affiliation as printed

   PSL Research University

3. Vincent Démery

   École Normale Supérieure de Lyon · Université de Lyon · Université Paris Sciences et Lettres

   Affiliation as printed

   PSL Research University

   Université de Lyon

   École Normale Supérieure de Lyon

4. Gustavo Düring

   Pontificia Universidad Católica de Chile

   Affiliation as printed

   Pontificia Universidad Católica de Chile

5. Silke Henkes Aachen

   Leiden University

   Affiliation as printed

   Leiden University

   Lorentz Institute

6. Cristián Huepe

   Northwestern University · Beijing Normal University

   Affiliation as printed

   Beijing Normal University

   CHuepe Labs

   Northwestern University

7. Amir Shee

   Northwestern University

   Affiliation as printed

   Northwestern University