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Active screws: Emergent active chiral nematics of spinning self-propelled rods

Debarghya Banerjee1, Lauritz Hahn2,3, and Ricard Alert2,3,4,5,6,7,*

  • *Contact author: ricard.alert@ub.edu
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Phys. Rev. Research 8, 033113 – Published 27 July, 2026

DOI: https://doi.org/10.1103/g9xx-g89r

Abstract

Several types of active agents self-propel by spinning around their propulsion axis, thus behaving as active screws. Examples include cytoskeletal filaments in gliding assays, magnetically driven colloidal helices, and microorganisms such as the bacterium Myxococcus xanthus. Here, we develop a model for spinning self-propelled rods on a substrate, and we coarse grain it to derive the corresponding hydrodynamic equations. If the rods propel purely along their axis, they form an active nematic at high density and activity. However, spinning rods can also roll sideways as they move. We find that this transverse motion turns the system into a chiral active nematic. Thus, we identify a mechanism whereby individual chirality can give rise to collective local chiral flows. Finally, we analyze experiments on M. xanthus colonies to show that they exhibit chiral flows around topological defects, with a chiral activity about an order of magnitude weaker than the achiral one. Our work reveals the collective behavior of active screws, which is relevant to colonies of social bacteria and groups of unicellular parasites.

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References (75)

  1. L. Meißner, L. Niese, and S. Diez, Helical motion and torque generation by microtubule motors, Curr. Opin. Cell Biol. 88, 102367 (2024).
  2. N. Wadhwa and H. C. Berg, Bacterial motility: Machinery and mechanisms, Nat. Rev. Microbiol. 20, 161 (2022).
  3. T. Mignot, J. W. Shaevitz, P. L. Hartzell, and D. R. Zusman, Evidence that focal adhesion complexes power bacterial gliding motility, Science 315, 853 (2007).
  4. R. Balagam, D. B. Litwin, F. Czerwinski, M. Sun, H. B. Kaplan, J. W. Shaevitz, and O. A. Igoshin, Myxococcus xanthus gliding motors are elastically coupled to the substrate as predicted by the focal adhesion model of gliding motility, PLoS Comput. Biol. 10, e1003619 (2014).
  5. S. T. Islam and T. Mignot, The mysterious nature of bacterial surface (gliding) motility: A focal adhesion-based mechanism in Myxococcus xanthus, Semin. Cell Dev. Biol. 46, 143 (2015).
  6. L. M. Faure, J.-B. Fiche, L. Espinosa, A. Ducret, V. Anantharaman, J. Luciano, S. Lhospice, S. T. Islam, J. Tréguier, M. Sotes, E. Kuru, M. S. Van Nieuwenhze, Y. V. Brun, O. Théodoly, L. Arvind, M. Nollmann, and T. Mignot, The mechanism of force transmission at bacterial focal adhesion complexes, Nature (London) 539, 530 (2016).
  7. D. Nakane, K. Sato, H. Wada, M. J. McBride, and K. Nakayama, Helical flow of surface protein required for bacterial gliding motility, Proc. Natl. Acad. Sci. USA 110, 11145 (2013).
  8. A. Shrivastava, P. P. Lele, and H. C. Berg, A rotary motor drives Flavobacterium gliding, Curr. Biol. 25, 338 (2015).
  9. A. Shrivastava and H. C. Berg, Towards a model for Flavobacterium gliding, Curr. Opin. Microbiol. 28, 93 (2015).
  10. A. Shrivastava, T. Roland, and H. C. Berg, The screw-like movement of a gliding bacterium is powered by spiral motion of cell-surface adhesins, Biophys. J. 111, 1008 (2016).
  11. T. H. Tan, A. Mietke, J. Li, Y. Chen, H. Higinbotham, P. J. Foster, S. Gokhale, J. Dunkel, and N. Fakhri, Odd dynamics of living chiral crystals, Nature (London) 607, 287 (2022).
  12. D. Cortese and K. Y. Wan, Control of helical navigation by three-dimensional flagellar beating, Phys. Rev. Lett. 126, 088003 (2021).
  13. K. Drescher, K. C. Leptos, I. Tuval, T. Ishikawa, T. J. Pedley, and R. E. Goldstein, Dancing Volvox: Hydrodynamic bound states of swimming algae, Phys. Rev. Lett. 102, 168101 (2009).
  14. L. Zhang, J. J. Abbott, L. Dong, B. E. Kratochvil, D. Bell, and B. J. Nelson, Artificial bacterial flagella: Fabrication and magnetic control, Appl. Phys. Lett. 94, 064107 (2009).
  15. A. Ghosh and P. Fischer, Controlled propulsion of artificial magnetic nanostructured propellers, Nano Lett. 9, 2243 (2009).
  16. S. Palagi and P. Fischer, Bioinspired microrobots, Nat. Rev. Mater. 3, 113 (2018).
  17. J. G. Gibbs and P. Fischer, Active colloidal microdrills, Chem. Commun. 51, 4192 (2015).
  18. E. Tjhung, M. E. Cates, and D. Marenduzzo, Contractile and chiral activities codetermine the helicity of swimming droplet trajectories, Proc. Natl. Acad. Sci. USA 114, 4631 (2017).
  19. L. N. Carenza, G. Gonnella, D. Marenduzzo, and G. Negro, Rotation and propulsion in 3D active chiral droplets, Proc. Natl. Acad. Sci. USA 116, 22065 (2019).
  20. C. Bechinger, R. Di Leonardo, H. Löwen, C. Reichhardt, G. Volpe, and G. Volpe, Active particles in complex and crowded environments, Rev. Mod. Phys. 88, 045006 (2016).
  21. B. Liebchen and D. Levis, Collective behavior of chiral active matter: Pattern formation and enhanced flocking, Phys. Rev. Lett. 119, 058002 (2017).
  22. B. Liebchen and D. Levis, Chiral active matter, Europhys. Lett. 139, 67001 (2022).
  23. M. J. Bowick, N. Fakhri, M. C. Marchetti, and S. Ramaswamy, Symmetry, thermodynamics, and topology in active matter, Phys. Rev. X 12, 010501 (2022).
  24. I. H. Riedel, K. Kruse, and J. Howard, A self-organized vortex array of hydrodynamically entrained sperm cells, Science 309, 300 (2005).
  25. E. Lauga, W. R. DiLuzio, G. M. Whitesides, and H. A. Stone, Swimming in circles: Motion of bacteria near solid boundaries, Biophys. J. 90, 400 (2006).
  26. A. P. Petroff, X. L. Wu, and A. Libchaber, Fast-moving bacteria self-organize into active two-dimensional crystals of rotating cells, Phys. Rev. Lett. 114, 158102 (2015).
  27. H. Li, H. Chaté, M. Sano, X.-q. Shi, and H. P. Zhang, Robust edge flows in swarming bacterial colonies, Phys. Rev. X 14, 041006 (2024).
  28. I. S. Aranson, Bacterial active matter, Rep. Prog. Phys. 85, 076601 (2022).
  29. K. Kim, N. Yoshinaga, S. Bhattacharyya, H. Nakazawa, M. Umetsu, and W. Teizer, Large-scale chirality in an active layer of microtubules and kinesin motor proteins, Soft Matter 14, 3221 (2018).
  30. Z. Dunajova, B. P. Mateu, P. Radler, K. Lim, D. Brandis, P. Velicky, J. G. Danzl, R. W. Wong, J. Elgeti, E. Hannezo, and M. Loose, Chiral and nematic phases of flexible active filaments, Nat. Phys. 19, 1916 (2023).
  31. F. Kümmel, B. Ten Hagen, R. Wittkowski, I. Buttinoni, R. Eichhorn, G. Volpe, H. Löwen, and C. Bechinger, Circular motion of asymmetric self-propelling particles, Phys. Rev. Lett. 110, 198302 (2013).
  32. B. A. Grzybowski, H. A. Stone, and G. M. Whitesides, Dynamic self-assembly of magnetized, millimetre-sized objects rotating at a liquid–air interface, Nature (London) 405, 1033 (2000).
  33. V. Soni, E. S. Bililign, S. Magkiriadou, S. Sacanna, D. Bartolo, M. J. Shelley, and W. T. M. Irvine, The odd free surface flows of a colloidal chiral fluid, Nat. Phys. 15, 1188 (2019).
  34. A. Bricard, J.-B. Caussin, N. Desreumaux, O. Dauchot, and D. Bartolo, Emergence of macroscopic directed motion in populations of motile colloids, Nature (London) 503, 95 (2013).
  35. J. Elgeti, R. G. Winkler, and G. Gompper, Physics of microswimmers-single particle motion and collective behavior: A review, Rep. Prog. Phys. 78, 056601 (2015).
  36. E. Lauga, Bacterial hydrodynamics, Annu. Rev. Fluid Mech. 48, 105 (2016).
  37. L. Lettermann, F. Ziebert, and U. S. Schwarz, A geometrical theory of gliding motility based on cell shape and surface flow, Proc. Natl. Acad. Sci. USA 121, e2410708121 (2024).
  38. C. L. Hueschen, L.-a. Segev-Zarko, J.-H. Chen, M. A. LeGros, C. A. Larabell, J. C. Boothroyd, R. Phillips, and A. R. Dunn, Emergent actin flows explain distinct modes of gliding motility, Nat. Phys. 20, 1989 (2024).
  39. L. Lettermann, F. Ziebert, M. Singer, F. Frischknecht, and U. S. Schwarz, Three-dimensional chiral active Ornstein-Uhlenbeck model for helical motion of microorganisms, Phys. Rev. Lett. 135, 128403 (2025).
  40. L. Lettermann, M. Singer, S. Steinbrück, F. Ziebert, S. Kanatani, P. Sinnis, F. Frischknecht, and U. S. Schwarz, Chirality of malaria parasites determines their motion patterns, Nat. Phys. 22, 112 (2026).
  41. A. Vilfan, L. Abbaspour, S. Villa, and V. Nasirimarekani, Chiral gliding: Right-handed navigation of filamentous cyanobacteria, Proc. Natl. Acad. Sci. USA 123, e2534547123 (2026).
  42. P. Patra, K. Beyer, A. Jaiswal, A. Battista, K. Rohr, F. Frischknecht, and U. S. Schwarz, Collective migration reveals mechanical flexibility of malaria parasites, Nat. Phys. 18, 586 (2022).
  43. M. G. Athani, N. Prouse, N. Sarpangala, P. Noerr, G. Schiano-Lomoriello, A. G. Kumar, F. L. Memarian, J. Gaillard, L. Blanchoin, L. S. Hirst, K. Dasbiswas, A. Gopinathan, O. Kučera, and D. A. Beller, Gliding microtubules exhibit tunable collective rotation driven by chiral active forces, arXiv:2507.00245.
  44. S. Chahal and B. Chakrabarti, Hydrodynamic instabilities in driven chiral suspensions, Phys. Rev. E 113, L023101 (2026).
  45. K. Copenhagen, R. Alert, N. S. Wingreen, and J. W. Shaevitz, Topological defects promote layer formation in Myxococcus xanthus colonies, Nat. Phys. 17, 211 (2021).
  46. E. Han, C. Fei, R. Alert, K. Copenhagen, M. D. Koch, N. S. Wingreen, and J. W. Shaevitz, Local polar order controls mechanical stress and triggers layer formation in Myxococcus xanthus colonies, Nat. Commun. 16, 952 (2025).
  47. M. C. Marchetti, J. F. Joanny, S. Ramaswamy, T. B. Liverpool, J. Prost, M. Rao, and R. A. Simha, Hydrodynamics of soft active matter, Rev. Mod. Phys. 85, 1143 (2013).
  48. M. Bär, R. Großmann, S. Heidenreich, and F. Peruani, Self-propelled rods: Insights and perspectives for active matter, Annu. Rev. Condens. Matter Phys. 11, 441 (2020).
  49. J. Herrou and T. Mignot, Dynamic polarity control by a tunable protein oscillator in bacteria, Curr. Opin. Cell Biol. 62, 54 (2020).
  50. Q. Vagne and G. Salbreux, Generic theory of interacting, spinning, active polar particles: A model for cell aggregates, Phys. Rev. E 111, 014423 (2025).
  51. P. Kraikivski, R. Lipowsky, and J. Kierfeld, Enhanced ordering of interacting filaments by molecular motors, Phys. Rev. Lett. 96, 258103 (2006).
  52. A. Baskaran and M. C. Marchetti, Enhanced diffusion and ordering of self-propelled rods, Phys. Rev. Lett. 101, 268101 (2008).
  53. S. Santhosh, M. R. Nejad, A. Doostmohammadi, J. M. Yeomans, and S. P. Thampi, Activity induced nematic order in isotropic liquid crystals, J. Stat. Phys. 180, 699 (2020).
  54. G. Liu, A. Patch, F. Bahar, D. Yllanes, R. D. Welch, M. C. Marchetti, S. Thutupalli, and J. W. Shaevitz, Self-driven phase transitions drive Myxococcus xanthus fruiting body formation, Phys. Rev. Lett. 122, 248102 (2019).
  55. S. Das, M. Ciarchi, Z. Zhou, J. Yan, J. Zhang, and R. Alert, Flocking by turning away, Phys. Rev. X 14, 031008 (2024).
  56. A. Maitra and M. Lenz, Spontaneous rotation can stabilise ordered chiral active fluids, Nat. Commun. 10, 920 (2019).
  57. A. Maitra, Activity unmasks chirality in liquid-crystalline matter, Annu. Rev. Condens. Matter Phys. 16, 275 (2025).
  58. M. E. Cates and J. Tailleur, Motility-induced phase separation, Annu. Rev. Condens. Matter Phys. 6, 219 (2015).
  59. T. Speck, Collective forces in scalar active matter, Soft Matter 16, 2652 (2020).
  60. J. Zhang, R. Alert, J. Yan, N. S. Wingreen, and S. Granick, Active phase separation by turning towards regions of higher density, Nat. Phys. 17, 961 (2021).
  61. S. Ramaswamy, R. A. Simha, and J. Toner, Active nematics on a substrate: Giant number fluctuations and long-time tails, Europhys. Lett. 62, 196 (2003).
  62. R. Großmann, I. S. Aranson, and F. Peruani, A particle-field approach bridges phase separation and collective motion in active matter, Nat. Commun. 11, 5365 (2020).
  63. S. Fürthauer, M. Strempel, S. W. Grill, and F. Jülicher, Active chiral fluids, Eur. Phys. J. E 35, 89 (2012).
  64. S. Fürthauer, M. Strempel, S. Grill, and F. Jülicher, Active chiral processes in thin films, Phys. Rev. Lett. 110, 048103 (2013).
  65. F. Jülicher, S. W. Grill, and G. Salbreux, Hydrodynamic theory of active matter, Rep. Prog. Phys. 81, 076601 (2018).
  66. B. Sabass, M. D. Koch, G. Liu, H. A. Stone, and J. W. Shaevitz, Force generation by groups of migrating bacteria, Proc. Natl. Acad. Sci. USA 114, 7266 (2017).
  67. L. A. Hoffmann, K. Schakenraad, R. M. H. Merks, and L. Giomi, Chiral stresses in nematic cell monolayers, Soft Matter 16, 764 (2020).
  68. V. Yashunsky, D. J. G. Pearce, C. Blanch-Mercader, F. Ascione, P. Silberzan, and L. Giomi, Chiral edge current in nematic cell monolayers, Phys. Rev. X 12, 041017 (2022).
  69. A. Barbot, D. Decanini, and G. Hwang, Controllable roll-to-swim motion transition of helical nanoswimmers, IEEE Int. Conf. Intell. Robot. Syst. 4662 (2014).
  70. X. Liang, Y. Ding, Z. Yuan, Y. Han, Y. Zhou, J. Jiang, Z. Xie, P. Fei, Y. Sun, P. Jia, G. Gu, Z. Zhong, F. Chen, G. Si, and Z. Gong, Mechanics of soft-body rolling motion without external torque, Phys. Rev. Lett. 134, 198401 (2025).
  71. A. Be'er, E. D. Neimand, D. Corbett, D. J. G. Pearce, G. Ariel, and V. Yashunsky, Irreversibility and symmetry breaking in the creation and annihilation of defects in active living matter, arXiv:2508.15622.
  72. S. Thutupalli, M. Sun, F. Bunyak, K. Palaniappan, and J. W. Shaevitz, Directional reversals enable Myxococcus xanthus cells to produce collective one-dimensional streams during fruiting-body formation, J. R. Soc. Interface 12, 20150049 (2015).
  73. C. Dinet, A. Michelot, J. Herrou, and T. Mignot, Linking single-cell decisions to collective behaviours in social bacteria, Phil. Trans. R. Soc. B 376, 20190755 (2021).
  74. A. Shrivastava, V. K. Patel, Y. Tang, S. C. Yost, F. E. Dewhirst, and H. C. Berg, Cargo transport shapes the spatial organization of a microbial community, Proc. Natl. Acad. Sci. USA 115, 8633 (2018).
  75. D. Nakane, S. Odaka, K. Suzuki, and T. Nishizaka, Large-scale vortices with dynamic rotation emerged from monolayer collective motion of gliding Flavobacteria, J. Bacteriol. 203, e00073 (2021).

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Phys. Rev. Research 8, 033113– Published 27 July, 2026
  • Received 16 October 2024
  • Accepted 6 July 2026
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Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Open access publication funded by Max Planck Society.

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