pith. sign in

arxiv: 2605.18242 · v1 · pith:NN3C2T44new · submitted 2026-05-18 · ❄️ cond-mat.soft

Modulating hydrodynamic flow by modifying the active patch of a colloid

Pith reviewed 2026-05-20 00:22 UTC · model grok-4.3

classification ❄️ cond-mat.soft
keywords active colloidshydrodynamic flowsmulti-particle collision dynamicspusher and pullerself-propulsionboundary conditionspatchy particles
0
0 comments X

The pith

Varying the size of an active surface patch on a colloid switches its generated hydrodynamic flow from pusher-type to puller-type.

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

This paper develops a simulation method to model fluid flows around colloids with a localized active patch that drives the surrounding fluid. By changing the area of this patch, the far-field flow pattern transitions from one that pushes fluid outward along the axis to one that pulls it inward. A hybrid boundary condition is introduced to handle the interaction between the multi-particle collision fluid and the colloid surface accurately. This allows the otherwise Brownian particle to become self-propelled while conserving momentum. Understanding this control over flow type matters because it opens ways to tune hydrodynamic interactions in suspensions of active particles.

Core claim

The authors show that systematically varying the surface area of the active patch on the colloid changes the nature of the generated flow field from that of a pusher to a puller. The model uses multi-particle collision dynamics with momentum exchange at the active surface, where fluid is driven radially away from or toward the patch, imparting opposite momentum to the colloid for self-propulsion.

What carries the argument

The active surface patch whose area is varied to control the flow field type, implemented via a hybrid boundary condition that combines no-slip enforcement with stochastic momentum exchange.

If this is right

  • Self-propulsion emerges in the Brownian colloid due to the surface-driven flow.
  • The model enables study of effective hydrodynamic interactions between active and passive colloids by adjusting patch size.
  • Interactions between two active colloids can be modulated similarly.
  • Future simulations can explore collective behaviors in systems with tunable pusher or puller characteristics.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • This patch-size control could serve as a design principle for engineering specific flow fields in synthetic active matter without changing particle shape or chemistry.
  • Experimental realizations with patchy colloids activated by light or chemical gradients might reproduce the pusher-to-puller transition.
  • Such modulation might affect the stability of clusters or the rheology of active suspensions in ways not captured by fixed-type approximations.

Load-bearing premise

The hybrid boundary condition correctly enforces no-slip while allowing momentum exchange between the MPC fluid and colloid surface without introducing artifacts that alter the far-field flow type.

What would settle it

Direct measurement or simulation of the velocity field far from the colloid for patches of varying fractional area, checking if the flow signature crosses from pusher (outward along axis) to puller (inward).

Figures

Figures reproduced from arXiv: 2605.18242 by Apratim Chatterji, Hemant Giri, Manish Modani, Om Vandra, Raghunath Chelakkot, Suhal Siva Ratan T. N., Vijay Chikkadi.

Figure 1
Figure 1. Figure 1: Mean kinetic energy (KE) of the SRD fluid for [PITH_FULL_IMAGE:figures/full_fig_p005_1.png] view at source ↗
Figure 2
Figure 2. Figure 2: (a) Poiseuille flow velocity profiles vflow for bounce-back, stochastic, and hybrid boundary conditions without virtual particles. A thermostat is applied only for the bounce-back case. (b) Corresponding profiles with virtual particles at the walls; here, a thermostat is applied for all three boundary conditions. The analytical no-slip profile is shown for reference. Panels (c) and (d) present zoomed-in vi… view at source ↗
Figure 3
Figure 3. Figure 3: (a) Probability distributions p(V ) and p(Ω) of the translational and rotational speeds of a passive colloid coupled to an MPCD fluid. The speeds are normalized as V /⟨V ⟩ and Ω/⟨Ω⟩, where ⟨V ⟩ = p 3kBT /Mcol and ⟨Ω⟩ = p 3kBT /Icol with kBT = 1 kBT0. The solid black lines denote the corresponding Maxwell–Boltzmann dis￾tributions. For this, calculate the updated force on the colloid f(t + ∆tmd) and use it t… view at source ↗
Figure 5
Figure 5. Figure 5: Schematic of cross section of the active col [PITH_FULL_IMAGE:figures/full_fig_p008_5.png] view at source ↗
Figure 6
Figure 6. Figure 6: Probability distribution of the velocity com [PITH_FULL_IMAGE:figures/full_fig_p009_6.png] view at source ↗
Figure 8
Figure 8. Figure 8: Kinetic energy (KE) of the fluid in the vicin [PITH_FULL_IMAGE:figures/full_fig_p010_8.png] view at source ↗
Figure 9
Figure 9. Figure 9: (a) Mean-square displacement (MSD) of a sin [PITH_FULL_IMAGE:figures/full_fig_p011_9.png] view at source ↗
Figure 10
Figure 10. Figure 10: Flow profiles around an active colloid for different values of [PITH_FULL_IMAGE:figures/full_fig_p012_10.png] view at source ↗
Figure 11
Figure 11. Figure 11: Flow profiles for an active colloid with [PITH_FULL_IMAGE:figures/full_fig_p013_11.png] view at source ↗
Figure 12
Figure 12. Figure 12: Fluid flow profiles around an active colloid [PITH_FULL_IMAGE:figures/full_fig_p014_12.png] view at source ↗
Figure 15
Figure 15. Figure 15: We also show the y component of the velocity of fluid v y f low along a line in the ˆy direction, i.e. perpen￾dicular to ˆe along a line next to the lateral axis. Data is plotted for different values of θ. The values of θ are given in the legend. Note that the fluid velocity inside the sphere is marked as zero, as there is no fluid inside. The top figure labeled (a) shows the flow magnitude for the outwar… view at source ↗
Figure 16
Figure 16. Figure 16: Probability distribution of the velocity of par [PITH_FULL_IMAGE:figures/full_fig_p017_16.png] view at source ↗
read the original abstract

We have developed a simulation model to study the hydrodynamic flow fields around Brownian colloidal particles with an active surface patch. Hydrodynamics is introduced by modeling low-Reynolds-number fluid flows around a colloid using multi-particle collision (MPC) dynamics and allowing momentum exchange between the MPC fluid and the colloid. This approach provides good estimates of both near- and far-field flows around the colloid. The size of the active patch is varied to generate different fluid flow fields around the colloid. In this framework, the fluid in the vicinity of the active patch is driven radially away from (or toward) the surface, and an equal and opposite momentum is imparted to the colloid to ensure momentum conservation. The resulting surface-driven flow generates self-propulsion of the particle, thereby converting an otherwise Brownian colloid into an active Brownian particle. Interestingly, as we systematically vary the surface area of the active patch on the colloid, the nature of the generated flow field changes from that of a pusher to a puller. To model such surface activity-driven flows, we developed a hybrid boundary condition that ensures a no-slip condition while incorporating momentum exchange between the flowing fluid and the colloid surface. This scheme integrates the advantages of bounce-back and stochastic boundary conditions while mitigating their respective limitations. Thus, in future studies, the effective hydrodynamic interactions between an active and a passive colloid, or between two active colloids, can be modulated by adjusting the size of the active patch.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

2 major / 2 minor

Summary. The manuscript presents an MPC-dynamics simulation of a Brownian colloid equipped with a tunable active surface patch. Radial activity is imposed on the patch while an equal-and-opposite momentum is imparted to the particle; a hybrid bounce-back/stochastic boundary condition is introduced to enforce no-slip at the colloid surface while permitting momentum exchange. Systematic variation of the active-patch area fraction is reported to drive a transition in the far-field flow from pusher-type to puller-type, thereby converting the particle into an active Brownian swimmer whose hydrodynamic signature can be modulated by patch size.

Significance. If the reported pusher-to-puller crossover survives quantitative validation, the work supplies a concrete, experimentally accessible handle (patch area) for tuning the hydrodynamic dipole of active colloids. This could directly inform design of micro-swimmers and studies of hydrodynamic interactions between active and passive particles. The hybrid boundary-condition scheme itself may be reusable in other MPC studies of surface-driven flows.

major comments (2)
  1. [hybrid boundary condition implementation] Section describing the hybrid boundary condition: the claim that the scheme 'ensures a no-slip condition while incorporating momentum exchange' without altering the far-field flow type is load-bearing for the central result, yet no quantitative test is provided that the extracted force-dipole coefficient retains the correct sign for patch radii below ~0.4R. In MPC, local momentum injection on the lattice can generate spurious higher-order multipoles that decay slower than 1/r^3; without a direct comparison to analytic squirmer solutions or a convergence study versus collision-cell size, it remains possible that the observed crossover is an artifact of the discrete implementation rather than a physical effect of patch area.
  2. [results on flow fields] Results section on flow-field characterization: the transition from pusher to puller is asserted on the basis of visual or qualitative inspection of streamlines, but the manuscript supplies neither error bars on the measured velocity fields nor an explicit definition of the dipole sign (e.g., the coefficient of the 1/r^2 term in the far-field expansion). Without these, the sharpness and robustness of the reported crossover cannot be assessed.
minor comments (2)
  1. [abstract] The abstract states that 'an equal and opposite momentum is imparted to the colloid'; a brief clarification of how this is implemented numerically (e.g., via direct force application or velocity rescaling) would improve reproducibility.
  2. [figures] Figure captions should explicitly state the patch area fractions shown and the distance at which the flow field is sampled to distinguish near-field from far-field behavior.

Simulated Author's Rebuttal

2 responses · 0 unresolved

We thank the referee for their thorough review and valuable feedback on our manuscript. We appreciate the opportunity to clarify and strengthen our presentation of the hybrid boundary condition and the flow field analysis. Below, we provide detailed responses to the major comments and indicate the revisions we will implement.

read point-by-point responses
  1. Referee: [hybrid boundary condition implementation] Section describing the hybrid boundary condition: the claim that the scheme 'ensures a no-slip condition while incorporating momentum exchange' without altering the far-field flow type is load-bearing for the central result, yet no quantitative test is provided that the extracted force-dipole coefficient retains the correct sign for patch radii below ~0.4R. In MPC, local momentum injection on the lattice can generate spurious higher-order multipoles that decay slower than 1/r^3; without a direct comparison to analytic squirmer solutions or a convergence study versus collision-cell size, it remains possible that the observed crossover is an artifact of the discrete implementation rather than a physical effect of patch area.

    Authors: We acknowledge the referee's valid concern regarding potential numerical artifacts in the MPC simulations. The hybrid boundary condition was designed to enforce no-slip while allowing momentum exchange, and our tests during development indicated that the far-field behavior aligns with expectations. However, to address this rigorously, in the revised manuscript we will add a quantitative comparison of the simulated velocity field for small patch sizes (below 0.4R) to the analytic squirmer solution, confirming the correct (negative) sign of the force-dipole coefficient. We will also include a convergence study varying the collision cell size to demonstrate that the pusher-to-puller transition is not affected by discretization effects. These additions will provide stronger evidence that the crossover is physical. revision: yes

  2. Referee: [results on flow fields] Results section on flow-field characterization: the transition from pusher to puller is asserted on the basis of visual or qualitative inspection of streamlines, but the manuscript supplies neither error bars on the measured velocity fields nor an explicit definition of the dipole sign (e.g., the coefficient of the 1/r^2 term in the far-field expansion). Without these, the sharpness and robustness of the reported crossover cannot be assessed.

    Authors: We agree that a more quantitative presentation would enhance the clarity and credibility of our results. In the revised version, we will include error bars on the velocity field data, derived from averages over an ensemble of independent simulation runs. Additionally, we will explicitly define and report the dipole coefficient by fitting the far-field velocity to the expected 1/r^2 decay term and extracting its sign and magnitude as a function of patch area. This will allow readers to evaluate the sharpness of the transition and its statistical robustness. revision: yes

Circularity Check

0 steps flagged

Direct MPC simulation of patch-size variation yields pusher-to-puller transition with no definitional or self-citation reduction

full rationale

The manuscript reports results from explicit multi-particle collision dynamics simulations in which the active patch area is an independent input parameter that is varied systematically. The observed change in far-field flow character (pusher versus puller) is an output of the numerical integration under the stated hybrid boundary condition; no equation, fitted coefficient, or uniqueness theorem is defined in terms of the same flow-type classification, and no load-bearing step reduces to a prior self-citation or ansatz that already encodes the target result. The derivation chain is therefore self-contained against external benchmarks.

Axiom & Free-Parameter Ledger

2 free parameters · 2 axioms · 0 invented entities

The model rests on standard low-Reynolds-number hydrodynamics and MPC collision rules; no new particles or forces are postulated. A few simulation parameters (patch size, activity strength) are varied but not fitted to match a target result.

free parameters (2)
  • active patch area fraction
    Varied systematically to observe flow-type transition; chosen by hand rather than derived.
  • activity strength (radial velocity at patch)
    Sets the magnitude of fluid driving; value not specified in abstract.
axioms (2)
  • domain assumption Low-Reynolds-number flow around a sphere can be accurately captured by MPC with momentum exchange at the surface.
    Invoked when introducing the MPC model for the colloid-fluid system.
  • ad hoc to paper The hybrid boundary condition preserves both no-slip and global momentum conservation without spurious torques or forces.
    Central to the new numerical scheme described in the abstract.

pith-pipeline@v0.9.0 · 5816 in / 1411 out tokens · 44106 ms · 2026-05-20T00:22:49.865534+00:00 · methodology

discussion (0)

Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.

Reference graph

Works this paper leans on

55 extracted references · 55 canonical work pages

  1. [1]

    The hydrodynam- ics of swimming microorganisms.Reports on progress in physics, 72(9):096601, 2009

    Eric Lauga and Thomas R Powers. The hydrodynam- ics of swimming microorganisms.Reports on progress in physics, 72(9):096601, 2009

  2. [2]

    Feeders and expellers, two types of animalcules with outboard cilia, have distinct surface interactions

    Praneet Prakash, Marco Vona, and Raymond E Gold- stein. Feeders and expellers, two types of animalcules with outboard cilia, have distinct surface interactions. Physical Review Fluids, 9(10):103101, 2024

  3. [3]

    Green algae as model organisms for biological fluid dynamics.Annual review of fluid me- chanics, 47(1):343–375, 2015

    Raymond E Goldstein. Green algae as model organisms for biological fluid dynamics.Annual review of fluid me- chanics, 47(1):343–375, 2015

  4. [4]

    Bacterial hydrodynamics.Annual Review of Fluid Mechanics, 48(1):105–130, 2016

    Eric Lauga. Bacterial hydrodynamics.Annual Review of Fluid Mechanics, 48(1):105–130, 2016

  5. [5]

    Sourav Ganguly and Kiran Raj. Hydrodynamics of biomicroswimmers: A comprehensive review of theoret- ical foundations, locomotion strategies, and emerging frontiers.European Journal of Mechanics-B/Fluids, page 204529, 2026

  6. [6]

    Hydrodynamics of squirmers: A review on stokesian principles, analytical frameworks, and recent advances.Physics of Fluids, 37(12), 2025

    Sourav Ganguly et al. Hydrodynamics of squirmers: A review on stokesian principles, analytical frameworks, and recent advances.Physics of Fluids, 37(12), 2025

  7. [7]

    Generalized squirming motion of a sphere.Journal of Engineering Mathematics, 88(1):1–28, 2014

    On Shun Pak and Eric Lauga. Generalized squirming motion of a sphere.Journal of Engineering Mathematics, 88(1):1–28, 2014

  8. [8]

    On the squirming motion of nearly spherical deformable bodies through liquids at very small reynolds numbers.Communications on pure and applied mathematics, 5(2):109–118, 1952

    Michael James Lighthill. On the squirming motion of nearly spherical deformable bodies through liquids at very small reynolds numbers.Communications on pure and applied mathematics, 5(2):109–118, 1952

  9. [9]

    A spherical envelope approach to ciliary propulsion.Journal of Fluid Mechanics, 46(1):199–208, 1971

    John R Blake. A spherical envelope approach to ciliary propulsion.Journal of Fluid Mechanics, 46(1):199–208, 1971

  10. [10]

    Spherical squirmers: models for swim- ming micro-organisms.IMA Journal of Applied Mathe- matics, 81(3):488–521, 2016

    Timothy J Pedley. Spherical squirmers: models for swim- ming micro-organisms.IMA Journal of Applied Mathe- matics, 81(3):488–521, 2016

  11. [11]

    Direct measurement of the flow field around swimming microorganisms.Physical Review Letters, 105(16):168101, 2010

    Knut Drescher, Raymond E Goldstein, Nicolas Michel, Marco Polin, and Idan Tuval. Direct measurement of the flow field around swimming microorganisms.Physical Review Letters, 105(16):168101, 2010

  12. [12]

    Fluid dynamics and noise in bacterial cell–cell and cell–surface scatter- ing.Proceedings of the National Academy of Sciences, 108(27):10940–10945, 2011

    Knut Drescher, J¨ orn Dunkel, Luis H Cisneros, Sujoy Ganguly, and Raymond E Goldstein. Fluid dynamics and noise in bacterial cell–cell and cell–surface scatter- ing.Proceedings of the National Academy of Sciences, 108(27):10940–10945, 2011

  13. [13]

    Fluid flows created by swimming bacteria drive self-organization in confined suspensions.Proceedings of the National Academy of Sciences, 111(27):9733–9738, 2014

    Enkeleida Lushi, Hugo Wioland, and Raymond E Gold- stein. Fluid flows created by swimming bacteria drive self-organization in confined suspensions.Proceedings of the National Academy of Sciences, 111(27):9733–9738, 2014

  14. [14]

    Dancing volvox: hydrodynamic bound states of swim- ming algae.Physical review letters, 102(16):168101, 2009

    Knut Drescher, Kyriacos C Leptos, Idan Tuval, Takuji Ishikawa, Timothy J Pedley, and Raymond E Goldstein. Dancing volvox: hydrodynamic bound states of swim- ming algae.Physical review letters, 102(16):168101, 2009

  15. [15]

    The 2025 motile active matter roadmap.Journal of Physics: Condensed Matter, 37(14):143501, 2025

    Gerhard Gompper, Howard A Stone, Christina Kurzthaler, David Saintillan, Fernado Peruani, Dmitry A Fedosov, Thorsten Auth, Cecile Cottin- Bizonne, Christophe Ybert, Eric Cl´ ement, et al. The 2025 motile active matter roadmap.Journal of Physics: Condensed Matter, 37(14):143501, 2025

  16. [16]

    Synthetic chemo- taxis and collective behavior in active matter.Accounts of chemical research, 51(12):2982–2990, 2018

    Benno Liebchen and Hartmut Lowen. Synthetic chemo- taxis and collective behavior in active matter.Accounts of chemical research, 51(12):2982–2990, 2018

  17. [17]

    Theory of ac- tive suspensions

    David Saintillan and Michael J Shelley. Theory of ac- tive suspensions. InComplex fluids in biological sys- tems: Experiment, theory, and computation, pages 319–

  18. [18]

    Ionic diffusiophoresis of active colloids via galvanic exchange reactions.Nano Letters, 25(19):7975–7980, 2025

    Zuyao Xiao, Juliane Simmchen, Ignacio Pagonabarraga, and Marco De Corato. Ionic diffusiophoresis of active colloids via galvanic exchange reactions.Nano Letters, 25(19):7975–7980, 2025

  19. [19]

    Phoretic motion in active matter.Journal of Fluid Mechanics, 922:A10, 2021

    John F Brady. Phoretic motion in active matter.Journal of Fluid Mechanics, 922:A10, 2021. 19

  20. [20]

    Structured light enables biomimetic swimming and versatile locomotion of photoresponsive soft microrobots.Nature materials, 15(6):647–653, 2016

    Stefano Palagi, Andrew G Mark, Shang Yik Reigh, Kai Melde, Tian Qiu, Hao Zeng, Camilla Parmeg- giani, Daniele Martella, Alberto Sanchez-Castillo, Nadia Kapernaum, et al. Structured light enables biomimetic swimming and versatile locomotion of photoresponsive soft microrobots.Nature materials, 15(6):647–653, 2016

  21. [21]

    Technology roadmap of micro/nanorobots.ACS nano, 19(27):24174–24334, 2025

    Xiaohui Ju, Chuanrui Chen, Cagatay M Oral, Semih Se- vim, Ramin Golestanian, Mengmeng Sun, Negin Bouzari, Xiankun Lin, Mario Urso, Jong Seok Nam, et al. Technology roadmap of micro/nanorobots.ACS nano, 19(27):24174–24334, 2025

  22. [22]

    Bioinspired micro- robots.Nature Reviews Materials, 3(6):113–124, 2018

    Stefano Palagi and Peer Fischer. Bioinspired micro- robots.Nature Reviews Materials, 3(6):113–124, 2018

  23. [23]

    Advanced biofabri- cation techniques of muscle cell-powered biohybrid robots.International Journal of Extreme Manufactur- ing, 8(1):012007, 2026

    Niyou Wang, Yipei Yang, Zahra Rezaei, Mar´ ıa Jos´ e Veana Hern´ andez, Kannan Govindaraj, Car- olina Vazquez Garzon, Marina Colin, Alan de Je- sus Alarcon Rodr´ ıguez, Alvaro Dario Martinez Blanco, Jose Joaquin Velasco, et al. Advanced biofabri- cation techniques of muscle cell-powered biohybrid robots.International Journal of Extreme Manufactur- ing, 8(...

  24. [24]

    Microrobots for pulmonary drug delivery

    Zhengxing Li, Hao Luan, Zheng Fang, Shichao Ding, Robert Kobrin, Ronnie H Fang, Liangfang Zhang, and Joseph Wang. Microrobots for pulmonary drug delivery. Nature Reviews Bioengineering, pages 1–17, 2026

  25. [25]

    Enzyme-powered hollow mesoporous janus nanomotors.Nano letters, 15(10):7043–7050, 2015

    Xing Ma, Anita Jannasch, Urban-Raphael Albrecht, Ker- sten Hahn, Albert Miguel-L´ opez, Erik Schaffer, and Samuel S´ anchez. Enzyme-powered hollow mesoporous janus nanomotors.Nano letters, 15(10):7043–7050, 2015

  26. [26]

    Enzyme-powered janus platelet cell robots for active and targeted drug delivery.Science Robotics, 5(43):eaba6137, 2020

    Songsong Tang, Fangyu Zhang, Hua Gong, Fanan Wei, Jia Zhuang, Emil Karshalev, Berta Esteban- Fern´ andez de ´Avila, Chuying Huang, Zhidong Zhou, Zhengxing Li, et al. Enzyme-powered janus platelet cell robots for active and targeted drug delivery.Science Robotics, 5(43):eaba6137, 2020

  27. [27]

    Bacterial outer membrane vesicle nanorobot.Proceedings of the National Academy of Sciences, 121(30):e2403460121, 2024

    Songsong Tang, Daitian Tang, Houhong Zhou, Yangyang Li, Dewang Zhou, Xiqi Peng, Chunyu Ren, Yilin Su, Shaohua Zhang, Haoxiang Zheng, et al. Bacterial outer membrane vesicle nanorobot.Proceedings of the National Academy of Sciences, 121(30):e2403460121, 2024

  28. [28]

    Active patchy colloids with shape-tunable dynamics.Journal of the American Chemical Society, 141(37):14853–14863, 2019

    Zuochen Wang, Zhisheng Wang, Jiahui Li, Simon Tsz Hang Cheung, Changhao Tian, Shin-Hyun Kim, Gi- Ra Yi, Etienne Ducrot, and Yufeng Wang. Active patchy colloids with shape-tunable dynamics.Journal of the American Chemical Society, 141(37):14853–14863, 2019

  29. [29]

    Hydrody- namic stokes flow induced by a chemically active patch imprinted on a planar wall.Journal of Colloid and In- terface Science, 690:137296, 2025

    Mihail N Popescu, Bogdan A Nicola, William E Uspal, Alvaro Dom´ ınguez, and Szilveszter G´ asp´ ar. Hydrody- namic stokes flow induced by a chemically active patch imprinted on a planar wall.Journal of Colloid and In- terface Science, 690:137296, 2025

  30. [30]

    Shape- anisotropic colloids at interfaces.Langmuir, 35(1):3–20, 2018

    Thriveni G Anjali and Madivala G Basavaraj. Shape- anisotropic colloids at interfaces.Langmuir, 35(1):3–20, 2018

  31. [31]

    Programmable hydrodynamics of active particles.arXiv preprint arXiv:2512.20752, 2025

    Lisa Rohde, Gordei Anchutkin, Viktor Holubec, and Frank Cichos. Programmable hydrodynamics of active particles.arXiv preprint arXiv:2512.20752, 2025

  32. [32]

    Self-propulsion of active colloids via ion release: Theory and experiments.Physical review letters, 124(10):108001, 2020

    Marco De Corato, Xavier Arqu´ e, Tania Pati˜ no, Marino Arroyo, Samuel S´ anchez, and Ignacio Pagonabarraga. Self-propulsion of active colloids via ion release: Theory and experiments.Physical review letters, 124(10):108001, 2020

  33. [33]

    Unravel- ling the role of phoretic and hydrodynamic interactions in active colloidal suspensions.Soft Matter, 16(38):8893– 8903, 2020

    Andrea Scagliarini and Ignacio Pagonabarraga. Unravel- ling the role of phoretic and hydrodynamic interactions in active colloidal suspensions.Soft Matter, 16(38):8893– 8903, 2020

  34. [34]

    Microfluidics: The no-slip boundary condition.Perspec- tive, 17:1, 2006

    Eric Lauga, Michael P Brenner, and Howard A Stone. Microfluidics: The no-slip boundary condition.Perspec- tive, 17:1, 2006

  35. [35]

    Combining molecular dynamics with lattice boltzmann: A hybrid method for the simulation of (charged) colloidal systems

    Apratim Chatterji and J¨ urgen Horbach. Combining molecular dynamics with lattice boltzmann: A hybrid method for the simulation of (charged) colloidal systems. The Journal of chemical physics, 122(18), 2005

  36. [36]

    A new model for simulating colloidal dynamics.New Journal of Physics, 6(1):54–54, 2004

    Vladimir Lobaskin and Burkhard D¨ unweg. A new model for simulating colloidal dynamics.New Journal of Physics, 6(1):54–54, 2004

  37. [37]

    Relevance of angular momentum conservation in mesoscale hydrodynamics simulations.Physical Re- view E—Statistical, Nonlinear, and Soft Matter Physics, 76(4):046705, 2007

    Ingo O G¨ otze, Hiroshi Noguchi, and Gerhard Gomp- per. Relevance of angular momentum conservation in mesoscale hydrodynamics simulations.Physical Re- view E—Statistical, Nonlinear, and Soft Matter Physics, 76(4):046705, 2007

  38. [38]

    Transport coef- ficients of off-lattice mesoscale-hydrodynamics simulation techniques.Physical Review E—Statistical, Nonlinear, and Soft Matter Physics, 78(1):016706, 2008

    Hiroshi Noguchi and Gerhard Gompper. Transport coef- ficients of off-lattice mesoscale-hydrodynamics simulation techniques.Physical Review E—Statistical, Nonlinear, and Soft Matter Physics, 78(1):016706, 2008

  39. [39]

    G Gompper, T Ihle, DM Kroll, and RG Winkler. Multi- particle collision dynamics: A particle-based mesoscale simulation approach to the hydrodynamics of complex fluids.Advanced computer simulation approaches for soft matter sciences III, pages 1–87, 2009

  40. [40]

    Particle-based mesoscale hydrodynamic techniques.EPL (Europhysics Letters), 78(1):10005, 2007

    Hiroshi Noguchi, Norio Kikuchi, and Gerhard Gompper. Particle-based mesoscale hydrodynamic techniques.EPL (Europhysics Letters), 78(1):10005, 2007

  41. [41]

    Devel- opment of a simulation model for solid objects suspended in a fluctuating fluid.Journal of statistical physics, 107(1):85–100, 2002

    Yasuhiro Inoue, Yu Chen, and Hirotada Ohashi. Devel- opment of a simulation model for solid objects suspended in a fluctuating fluid.Journal of statistical physics, 107(1):85–100, 2002

  42. [42]

    Mesoscopic model for solvent dynamics.The Journal of chemical physics, 110(17):8605–8613, 1999

    Anatoly Malevanets and Raymond Kapral. Mesoscopic model for solvent dynamics.The Journal of chemical physics, 110(17):8605–8613, 1999

  43. [43]

    Fluid–solid boundary conditions for multiparticle collision dynamics

    Jonathan K Whitmer and Erik Luijten. Fluid–solid boundary conditions for multiparticle collision dynamics. Journal of Physics: Condensed Matter, 22(10):104106, 2010

  44. [44]

    Simulation of claylike colloids.Physical Re- view E—Statistical, Nonlinear, and Soft Matter Physics, 72(1):011408, 2005

    Martin Hecht, Jens Harting, Thomas Ihle, and Hans J Herrmann. Simulation of claylike colloids.Physical Re- view E—Statistical, Nonlinear, and Soft Matter Physics, 72(1):011408, 2005

  45. [45]

    No-slip boundary conditions and forced flow in multiparticle collision dynamics.Phys- ical Review E—Statistical, Nonlinear, and Soft Matter Physics, 86(6):066703, 2012

    Dan S Bolintineanu, Jeremy B Lechman, Steven J Plimp- ton, and Gary S Grest. No-slip boundary conditions and forced flow in multiparticle collision dynamics.Phys- ical Review E—Statistical, Nonlinear, and Soft Matter Physics, 86(6):066703, 2012

  46. [46]

    Multi-particle collision dynamics: Flow around a circular and a square cylinder.Europhysics Letters, 56(3):319, 2001

    Antonio Lamura, Gerhard Gompper, Thomas Ihle, and DM Kroll. Multi-particle collision dynamics: Flow around a circular and a square cylinder.Europhysics Letters, 56(3):319, 2001

  47. [47]

    Simulating squirm- ers with multiparticle collision dynamics.The European Physical Journal E, 41(5):61, 2018

    Andreas Z¨ ottl and Holger Stark. Simulating squirm- ers with multiparticle collision dynamics.The European Physical Journal E, 41(5):61, 2018

  48. [48]

    Oxford university press, 2017

    Michael P Allen and Dominic J Tildesley.Computer sim- ulation of liquids. Oxford university press, 2017

  49. [49]

    Gpu-based multiscale sim- ulation to model active matter hydrodynamics in fluid medium

    SUHAL SIVA RATAN TN. Gpu-based multiscale sim- ulation to model active matter hydrodynamics in fluid medium. 2023

  50. [50]

    Fluid flow profiles for other values ofθis available in suuplementary information at [url]

  51. [51]

    JT Padding, A Wysocki, H L¨ owen, and AA Louis. Stick boundary conditions and rotational velocity auto- 20 correlation functions for colloidalparticles in a coarse- grained representation of the solvent.Journal of physics: Condensed matter, 17(45):S3393, 2005

  52. [52]

    Role of viscoelasticity on the dynamics and ag- gregation of chemically active sphere-dimers.Physics of Fluids, 33(1), 2021

    Soudamini Sahoo, Sunil Pratap Singh, and Snigdha Thakur. Role of viscoelasticity on the dynamics and ag- gregation of chemically active sphere-dimers.Physics of Fluids, 33(1), 2021

  53. [53]

    Dynamics of self- propelled nanomotors in chemically active media.The Journal of chemical physics, 135(2), 2011

    Snigdha Thakur and Raymond Kapral. Dynamics of self- propelled nanomotors in chemically active media.The Journal of chemical physics, 135(2), 2011

  54. [54]

    Diffusiophoretic brownian dynamics: characterization of hydrodynamic effects for an active chemoattractive poly- mer.Macromolecules, 57(15):6968–6978, 2024

    Surabhi Jaiswal, Marisol Ripoll, and Snigdha Thakur. Diffusiophoretic brownian dynamics: characterization of hydrodynamic effects for an active chemoattractive poly- mer.Macromolecules, 57(15):6968–6978, 2024

  55. [55]

    Hydrodynamics flow fields around an active patchy colloid, GitHub Repos- itory.https://github.com/captn-nem0/paper1_data

    Om Vandra and Apratim Chatterji. Hydrodynamics flow fields around an active patchy colloid, GitHub Repos- itory.https://github.com/captn-nem0/paper1_data. git, 2026