Pith. sign in

REVIEW 2 major objections 5 minor 105 references

Sedimentation and structure of squirmer suspensions under gravity

T0 review · 2 major / 5 minor · reviewed 2026-08-12 · deepseek-v4-flash

Pith's one-line read In sedimenting suspensions of model microswimmers, increasing gravity drives the bottom monolayer into a hexagonal crystal, and puller-type swimmers reach a nearly defect-free crystal at lower gravitational forcing than pushers or passive…

desk verdict A credible, honest DPD simulation study with a new qualitative claim about pullers annealing defects in sedimented monolayers, but the headline comparison rests on an untested shape-neutrality assumption. read the letter →

arxiv 2411.13359 v1 pith:J2MO5QVE submitted 2024-11-20 cond-mat.soft

classification cond-mat.soft
keywords squirmersuspensionssedimentationdissipativeparticledynamicshexagonalorderactivecolloidspullerandpusherswimmerswallorientationmonolayercrystallization
verification ladder T0 review T1 audit T2 compute T3 formal

The pith

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

The reading

The paper uses coarse-grained dissipative-particle-dynamics simulations of 500 "raspberry" colloids to ask how gravity and self-propulsion jointly shape where microswimmers settle and what structure the sedimented layer takes. It shows that as the gravitational force increases, the bottom monolayer of passive colloids, pullers, and pushers all move toward a hexagonal crystal, but the path differs: passive colloids get kinetically trapped with defects, while active swimmers keep rearranging and anneal those defects. Among swimmers, pullers preserve hexagonal order better than pushers, forming an almost perfect hexagonal crystal at lower gravitational fields. The authors take this as evidence that the sign of the swimmer's stresslet, whether it pulls fluid in at the equator or pushes it out, controls both wall orientation and how easily a sedimented monolayer heals. These results matter because settling of biological microswimmers underlies biofilm formation and bioconvection, so swimmer-type-dependent order could affect how dense, structured microbial layers form.

What carries the argument

The argument runs on the raspberry-DPD squirmer: each colloid is a rigid body of 19 DPD beads (18 fillers on a sphere plus a central thruster), and self-propulsion is imposed through a force field on solvent particles in a shell around the colloid, $\mathbf{F}_H(r,\theta) = (B_1\sin\theta + B_2\sin\theta\cos\theta)\,\hat{\mathbf{e}}_\theta$, with $\beta = B_2/B_1$ positive for pullers and negative for pushers. The structural analysis is carried by the local hexagonal-order parameter $\psi_6$, its correlation function $G_6(r)$, the static structure factor, and the distribution of wall-orientation angles $\alpha$. The mechanism that distinguishes swimmer types is the wall-induced hydrodynamic torque: pullers reorient toward the wall and stay persistently tilted, while pushers prefer orientations parallel to the wall, making them more motile and more disruptive to the hexagonal layer.

What would settle it

Run the same bottom-layer simulations with effectively spherical colloids, for example with conservative interactions only on the central thruster bead or with a raspberry made of many more fillers, and compare $\psi_6$, the wall-angle peaks, and the $F_g/F_p$ at which crystallinity appears. If the puller advantage in preserving hexagonal order shrinks or the preferred wall angles move away from the polyhedron face angles reported in the supplementary material, the central claim is an artifact of raspberry shape rather than a property of the stresslet sign.

Watch

Extended reading notes

Core claim

On the paper's own terms, the central discovery is that a sedimented bed of active colloids is not passively frozen: activity lets the bottom layer escape kinetic trapping and reorganize into an ordered state, and the type of activity selects how perfect that order is. At the two strongest gravitational fields, puller suspensions show a pronounced peak in the hexagonal-order parameter at $\psi_6 \approx 0.95$ already at $F_g/F_p = 1.50$, and their hexagonal correlation function $G_6(r)$ does not decay, as expected for a crystal; pushers need the highest field, $F_g/F_p = 2.25$, to reach the same crystalline signature, and at $F_g/F_p = 1.50$ they show a power-law decay consistent with a hexatic phase. Passive colloids form a hexagonal structure full of defects because thermal motion cannot overcome the trapped states. The explanation offered is hydrodynamic: pullers tend to point toward the wall with stable orientations, which hinders their lateral mobility and protects the lattice, whereas pushers align more parallel to the wall, stay more motile, and are more prone to disrupt the layer.

Load-bearing premise

The conclusion that pullers preserve hexagonal order better than pushers rests on the assumption that the small departures from perfect sphericity in the 19-bead colloid affect pullers and pushers identically, so every difference between them is caused by their swimming mechanism rather than by shape.

Editorial extensions

If this is right

  • If puller suspensions crystallize at lower gravity, gravitational settling of puller-like microalgae will produce sedimented monolayers with fewer defects at the same forcing, which changes how one predicts biofilm and bio-sediment microstructure from swimmer type.
  • Since activity removes kinetic trapping, active sedimented layers can anneal defects on simulation timescales where passive layers cannot; the quality of the crystal is set by the competition between gravitational compression and swimmer mobility.
  • The exponential sedimentation regime at moderate gravity reproduces the known trend that sedimentation lengths are larger for pushers than pullers and shrink with stronger gravity, so the model is consistent with earlier LB and MPCD results.
  • At high gravity, wall orientations converge to a common roughly 120 degrees toward-wall and 60 degrees away-from-wall population, meaning hydrodynamic swimmer-type differences are strongest in the transition regime rather than in the deep-crystal regime.

Reading between the lines

Editorial extensions of the paper, not claims the author makes directly.

  • If stresslet sign alone drives the defect-annealing gap, then a purely steric active colloid without hydrodynamics should lose the puller/pusher difference; this is a direct numerical lever to test the proposed mechanism.
  • By the same logic, pusher-like bacteria such as E. coli should produce more defective sedimented monolayers than puller-like algae, which could give a physical explanation for heterogeneous biofilm structure.
  • The near-perfect hexagonal order achieved by pullers suggests a possible route to gravity-assisted colloidal crystal templating using active colloids, where defects self-heal before the bed freezes.
  • A natural next step the paper leaves implicit is to measure how long a single defect takes to anneal as a function of $\beta$ and $F_g$; if the annealing rate is maximal at intermediate puller strength, the effect would be tunable.
Share X Bluesky LinkedIn Reddit HN

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, and a circularity audit.

Referee Report

2 major / 5 minor

Summary. This manuscript uses dissipative particle dynamics simulations of 19-bead raspberry squirmer colloids immersed in an explicit DPD solvent, under a gravitational force applied to the colloids, to study sedimentation and the structure of the sedimented bottom layer for passive colloids, pullers (β = +10), and pushers (β = −10). The passive sedimentation velocity is validated against Stokes law with a fitted effective radius, and the squirmer sedimentation profiles are compared with earlier MPCD and LB studies, reproducing known trends such as stronger wall accumulation for pullers and longer sedimentation lengths for pushers. The main new claim is that, as the gravitational field increases, the bottom layer undergoes a transition to a hexagonal crystal, that activity helps anneal defects relative to the kinetically trapped passive case, and that pullers preserve hexagonal order better than pushers, reaching an almost defect-free crystalline state at lower Fg. The structural analysis uses P(ψ6), G6(r), g(r), the static structure factor, polar order parameters, and orientation distributions P(α). The authors are appropriately cautious about the model's limitations, explicitly stating that lubrication forces are not included and that quantitative predictions are not the goal.

Significance. If the central claim survives scrutiny, the paper makes a useful contribution by demonstrating, within a single DPD model, that activity and specifically puller-type swimming accelerate the formation of nearly defect-free hexagonal monolayers in sedimented squirmer suspensions, and by connecting this to known wall-alignment hydrodynamics. The manuscript has real strengths: it validates the model against Stokes law and against independent MPCD/LB results, it describes the model and its parameters in detail, and it explicitly quantifies the expected size of lubrication effects. However, the load-bearing comparison between pullers and pushers currently rests on a single simulation protocol and on an untested assumption that the raspberry polyhedral shape affects both swimmers identically. The significance is therefore conditional on additional controls and statistical support.

major comments (2)
  1. [§3.2, §3.3, SM Fig. 7] The statement in §3.2 that 'the effects due to weak departure from sphericity are the same in both' is load-bearing for the central claim of §3.3 that pullers are better than pushers at preserving hexagonal order, but it is only asserted, not demonstrated. SM Fig. 7 shows that the 19-bead raspberry has preferred facet normals at 30.4°, 54.7°, and 69.1°, with supplements at 149.6°, 125.3°, and 110.9°, values that are suspiciously close to the observed P(α) peaks (≈125° and ≈155° for pullers, ≈125° for pushers, and ≈60° and ≈125° at high Fg). Because the propulsion reaction force is applied to the nearest filler particle (Eq. 4) and the B2 term changes sign between pullers and pushers, the discrete polyhedral surface can in principle produce a β-dependent effective wall torque or wall–colloid coupling. The paper's own §3.3 attributes the high-gravity orientation angles to 'the swimmers' raspberry structures', which further weakens the 'same in both' assumption. A control simulation with a spherical colloid—which the manuscript itself notes in §2.1.2 is achievable by switching off the filler conservative interactions—or an explicit calculation showing that the shape-induced free-energy landscape is identical for β and −β is required before the ordering difference can be attributed to the stresslet sign.
  2. [§3.3, Figs. 5 and 6] The claim that pullers undergo the hexagonal-order transition at smaller Fg than pushers is based on visual comparison of P(ψ6) distributions and G6(r) curves from what appears to be a single independent run per state point. The text says averages are taken over 600 independent configurations, but no information is given about the time separation between them or the number of independent initial conditions; if the configurations come from a single trajectory, the differences at Fg/Fp = 1.5 and 2.25 could be within run-to-run fluctuations. With only 500 colloids (and fewer in the bottom layer at low Fg), finite-size fluctuations are non-negligible. I recommend reporting ⟨ψ6⟩ or the fraction of particles with ψ6 above a threshold as a function of Fg, with standard errors or confidence intervals from independent runs, and stating a quantitative criterion for 'hexagonal crystal' (e.g., a plateau in G6(r) or a decay exponent) to replace the qualitative 'virtually overlapping' comparison.
minor comments (5)
  1. [Introduction] In the sentence about colloidal beads, 'not only onserved the same non-linear behaviour' should read 'observed'.
  2. [§3.2] 'zoom avaible in SM' contains a typo; it should be 'available'.
  3. [§4 Conclusions] The phrase 'previously reported bioconvenction' contains a typo; it should be 'bioconvection'.
  4. [Fig. 4 caption] The caption defines the 'Static Structure Factor (SFF)', but the acronym used throughout the text is SSF; please make this consistent.
  5. [Table 1 and footnote in §2.1.2] The table caption begins 'T able 1' and the footnote contains 'rencently'; both are typos.

Circularity Check

0 steps flagged · score 0.0 of 10

No circularity: the bottom-layer ordering result is generated by direct simulation, with no fitted target or self-citation chain in the derivation.

full rationale

The paper's central claim—that pullers preserve hexagonal order in the sedimented bottom layer better than pushers—is an observation from DPD simulations (Figs. 4–6), not a quantity derived from a fitted parameter or from the authors' prior work. The squirmer force field (Eq. 2) is the standard Lighthill/Blake two-mode expansion, and the propulsion force is prescribed as Fp = 2B1/3 rather than fitted. The only fits in the paper are validation ancillaries: the effective sedimentation radius in §2.2.1 and the exponential sedimentation lengths in §3.2, both compared against independent results (refs. 35, 36, 82). These fitted quantities do not feed into the hexagonal-order analysis. The authors' model reference (ref. 52) and their other self-citations (e.g., ref. 17) are methodological or contextual; the load-bearing comparisons are against independent LB/MPCD and experimental studies (refs. 35, 36, 40, 45, 50, 91, 92). The paper explicitly acknowledges limitations of the raspberry model—'the deviations in sphericity it introduces ... are small' and later 'the absence of lubrication corrections and the asphericity of the colloid'—which are honesty statements about robustness, not circular reductions. The skeptical concern that the puller/pusher difference could be modulated by the polyhedral filler arrangement is a validity/control-question issue (would a spherical-colloid control change the conclusion?), not a self-definitional or fitted-input circularity: the simulation output is not equivalent to any input assumption by construction. No step in the paper equates a prediction with a fitted value, a definition with a target, or an independent result with a self-citation. Accordingly, the circularity score is 0.

Assumptions & free parameters 6 free parameters · 5 assumptions · 0 invented entities

The paper is a coarse-grained simulation study; the numbers listed above are simulation inputs and validation fits, not fitted constants of a theory. The central claims rest on modeling assumptions about the squirmer force field, the adiabatic elimination of lubrication, and the shape-independence of the asphericity bias. No new physical entities are introduced.

free parameters (6)
  • Propulsion force field amplitude B1 = B1 = 50 (DPD units), giving Fp = 2B1/3 = 100/3
    Chosen by hand; sets swimming speed. Central to the puller/pusher comparison, since both use the same speed. Changing B1 could alter the gravity ratio Fg/Fp where ordering occurs.
  • Squirmer parameter beta = B2/B1 = beta = +10 (puller) and -10 (pusher)
    Chosen by hand; defines swimmer type. The strength (|beta|=10) is large; the ordering difference between pullers and pushers is the paper's main claim, so results may depend on this magnitude.
  • Gravitational force scan = Fg/Fp = {0, 0.15, 0.3, 0.5, 0.7, 0.75, 1.0, 1.5, 2.25}
    Independent variable scanned by hand; the transition to hexagonal order is reported as a function of this ratio.
  • Nearest-neighbor cutoff r_psi6 = 6.0 Rss
    Chosen as approximately the first minimum of g(r) at strong gravity; determines psi6 and P(Pl) values. Different cutoffs would shift the order parameter distributions.
  • Effective sedimentation radius (fit) = R = 1.55 Rss
    Fitted to Stokes law from the {Fg, vg} data in fig. 2 during model validation; ancillary to the central claim, but an example of a fit labeled as comparison.
  • Sedimentation lengths delta (fits) = delta_pull=5.27, delta_push=9.96 (Fg/Fp=0.15); 2.5, 3.41 (Fg/Fp=0.3), in RRDF units
    Obtained by fitting the 2D packing fraction to phi_2D = e^{z/delta} between chosen heights; used to compare with ref. 36.
assumptions (5)
  • domain assumption The squirmer flow field is represented by the truncated tangential force field of Eq. (2) (only B1 and B2 surface modes, radial component neglected) applied in the shell Rc<r<RH.
    This replaces a surface velocity boundary condition with a body-force field; all swimming behavior in the paper derives from it (Section 2.1.2). The truncation ignores higher modes that can matter near walls.
  • domain assumption DPD resolves hydrodynamics down to the coarse-graining scale Rss, and the missing lubrication divergence is not important for the reported ordering.
    The paper states near-field hydrodynamics is captured but lubrication is not, and estimates the lubrication torque correction (T~50) is small relative to the average torque (~600) (Section 2.1.3). If lubrication were important at the small gaps measured (0.7-1.0 body lengths), the defect-annealing comparison could change.
  • domain assumption The slight polyhedral asphericity of the 19-bead raspberry affects pullers and pushers identically.
    Invoked in Section 3.2 to attribute puller/pusher differences to hydrodynamics. SM fig. 7 shows facet normals at 60.0, 125.3 and 149.6 degrees, close to the observed preferred orientation angles, so this assumption is load-bearing and not directly tested.
  • domain assumption The sedimented bottom layer is in a representative steady state for active systems, and the passive reference, despite being kinetically trapped, is a valid baseline.
    Averages are taken over 600 configurations, but the authors admit passive colloids are kinetically trapped and would reach perfect hexagonal order on longer times (Section 3.3). The 'activity anneals defects' comparison is therefore a kinetic statement, valid only if the simulation time is long enough for the active systems to be representative.
  • standard math Standard DPD fluctuation-dissipation relation sigma = sqrt(2 k_B T gamma).
    Used to set the thermostat (Section 2.1.1); standard DPD framework.

how reviews work

0 comments
Cite this review

Pith. "Pith review of Sedimentation and structure of squirmer suspensions under gravity." pith.science (2026). https://pith.science/paper/J2MO5QVE

@misc{pith2026241113359,
  author       = {Pith},
  title        = {Pith review of: Sedimentation and structure of squirmer suspensions under gravity},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/J2MO5QVE}},
  note         = {Machine review of arXiv:2411.13359}
}
read the original abstract

The effect of gravity on the collective motion of living microswimmers, such as bacteria and micro-algae, is pivotal to unravel not only bio-convection patterns but also the settling of bacterial biofilms on solid surfaces. In this work, we investigate suspensions of microswimmers under the influence of a gravitational field and hydrodynamics, simulated via dissipative particle dynamics (DPD) coarse-grained model. We first study the collective sedimentation of passive colloids and microswimmers of the puller and pusher types upon increasing the imposed gravitational field and compare with previous results. Once sedimentation occurs, we observe that, as the gravitational field increases, the bottom layer undergoes a transition to an ordered state compatible with a hexagonal crystal. In comparison with passive colloids, both pullers and pushers easily rearrange at the bottom layer to anneal defects. Specifically, pullers are better than pushers in preserving the hexagonal order of the bottom mono-layer at high gravitational fields.

Figures

Figures reproduced from arXiv: 2411.13359 by the authors.

Figure 1
Figure 1. Left: Passive colloids boundary condition in bulk without gravity. Right: Temperature profile along the vertical and average norm of the solvent velocity in the passive colloidal dispersion under gravity Fg = 34 [PITH_FULL_IMAGE:figures/full_fig_p016_1.png] view at source ↗
Figure 2
Figure 2. Left and center: Sedimentation trajectories (light colors) and their average (dark colors) for the 100 topmost initialized colloids. Right: Sedimentation lengths, δ, computed by fitting sedimentation profile in the shown range to ϕ2D = e z/δ. In the legend α is just the inverse of Fg/Fp to compare with [1] [PITH_FULL_IMAGE:figures/full_fig_p016_2.png] view at source ↗
Figure 3
Figure 3. Left: Zoom on first layer using a bin width of ∆z = 0.044. Right: Zoom on second layer using a bin width of ∆z = 0.044. 1 arXiv:2411.13359v1 [cond-mat.soft] 20 Nov 2024 [PITH_FULL_IMAGE:figures/full_fig_p016_3.png] view at source ↗
Figures from the paper (6 more)
Figure 4
Figure 4. Figure 4: Maxima of the two dimensional packing fraction for 1st layer (left), the 2nd layer (center) and the interface [PITH_FULL_IMAGE:figures/full_fig_p017_4.png]
Figure 5
Figure 5. Figure 5: Top row: pullers. Bottom row: pushers. To be compared with fig. 6 of ref. [2], fig. 11 of ref. [3], fig. 2 of ref. [4] and fig. 2 of ref. [5] [PITH_FULL_IMAGE:figures/full_fig_p017_5.png]
Figure 6
Figure 6. Figure 6: Top: The spatial orientation correlation functions computed with the projection of the orientation of the squirmers onto the xy plane. From left to right: Fg/Fp = 0.0, 0.75, 1.5, 2.25. Bottom: Distributions for local polarization computed with the projection of the ori…
Figure 7
Figure 7. Figure 7: Top: Equatorial section of the force field generated by the conservative interaction of the raspberry colloid composed of 19 particles (red dots) for a DPD cutoff of rc = 1.5, A = 20 (left) and rc = 3, A = 150 (center). Polyhedral structure of the colloid (right), the …
Figure 8
Figure 8. Figure 8: DPD conservative force field and equal force surfaces (color) for smaller a wall region (dashed rectangle) [PITH_FULL_IMAGE:figures/full_fig_p019_8.png]
Figure 9
Figure 9. Figure 9: Radial distribution functions. Left: for colloids. Right: for walls. 1st row: passive case without gravity. 2nd row: passive case for Fg = 50. 3rd row: Pullers Fp = 16.67 case for Fg = 0.0. 4th row: Pushers Fp = 16.67 case for Fg = 0.0. 5th row: Pullers Fp = 33.33 case…

Discussion (0). Continue with ORCID to comment.

Reference graph

Works this paper leans on

105 extracted references · 79 canonical work pages

  1. [1]

    J.-T. Kuhr, J. Blaschke, F. R \"u hle, and H. Stark, ``Collective sedimentation of squirmers under gravity,'' Soft Matter , vol. 13, no. 41, pp. 7548--7555, 2017

  2. [2]

    Scagliarini and I

    A. Scagliarini and I. Pagonabarraga, ``Hydrodynamic and geometric effects in the sedimentation of model run-and-tumble microswimmers,'' Soft Matter , vol. 18, no. 12, pp. 2407--2413, 2022

  3. [3]

    Li and A

    G.-J. Li and A. M. Ardekani, ``Hydrodynamic interaction of microswimmers near a wall,'' Physical Review E , vol. 90, p. 013010, July 2014

  4. [4]

    J.-T. Kuhr, F. R \"u hle, and H. Stark, ``Collective dynamics in a monolayer of squirmers confined to a boundary by gravity,'' Soft Matter , vol. 15, no. 28, pp. 5685--5694, 2019

  5. [5]

    Enculescu and H

    M. Enculescu and H. Stark, ``Active Colloidal Suspensions Exhibit Polar Order under Gravity ,'' Physical Review Letters , vol. 107, p. 058301, July 2011

  6. [6]

    Gompper, R

    G. Gompper, R. G. Winkler, T. Speck, A. Solon, C. Nardini, F. Peruani, H. L \"o wen, R. Golestanian, U. B. Kaupp, L. Alvarez et al., Journal of Physics: Condensed Matter, 2020, 32, 193001

  7. [7]

    M. C. Marchetti, J.-F. Joanny, S. Ramaswamy, T. B. Liverpool, J. Prost, M. Rao and R. A. Simha, Reviews of modern physics, 2013, 85, 1143

  8. [8]

    Stark, The European Physical Journal Special Topics, 2016, 225, 2369--2387

    H. Stark, The European Physical Journal Special Topics, 2016, 225, 2369--2387

Show all 105 references
  1. [9]

    Javadi, J

    A. Javadi, J. Arrieta, I. Tuval and M. Polin, Philosophical Transactions of the Royal Society A, 2020, 378, 20190523

  2. [10]

    M. A. Bees, Annual Review of Fluid Mechanics, 2020, 52, 449--476

  3. [11]

    Pedley and J

    T. Pedley and J. Kessler, Science Progress (1933-), 1992, 105--123

  4. [12]

    Alloui, T

    Z. Alloui, T. Nguyen and E. Bilgen, International journal of heat and mass transfer, 2007, 50, 1435--1441

  5. [13]

    Ramamonjy, P

    A. Ramamonjy, P. Brunet and J. Dervaux, Journal of Fluid Mechanics, 2023, 971, A29

  6. [14]

    A. Kage, C. Hosoya, S. A. Baba and Y. Mogami, Journal of Experimental Biology, 2013, 216, 4557--4566

  7. [15]

    Lynch, K

    S. Lynch, K. Mukundakrishnan, M. Benoit, P. Ayyaswamy and A. Matin, Applied and environmental microbiology, 2006, 72, 7701--7710

  8. [16]

    R. J. McLean, J. M. Cassanto, M. B. Barnes and J. H. Koo, FEMS Microbiology Letters, 2001, 195, 115--119

  9. [17]

    D. R. Korber, J. R. Lawrence, L. Zhang and D. E. Caldwell, Biofouling, 1990, 2, 335--350

  10. [18]

    S. J. Ebbens and D. A. Gregory, Accounts of chemical research, 2018, 51, 1931--1939

  11. [19]

    Sharan, Z

    P. Sharan, Z. Xiao, V. Mancuso, W. E. Uspal and J. Simmchen, ACS nano, 2022, 16, 4599--4608

  12. [20]

    D. P. Singh, W. E. Uspal, M. N. Popescu, L. G. Wilson and P. Fischer, Advanced Functional Materials, 2018, 28, 1706660

  13. [21]

    M. R. Bailey, F. Grillo, N. D. Spencer and L. Isa, Advanced Functional Materials, 2022, 32, 2109175

  14. [22]

    M. R. Bailey, C. M. B. Guti \'e rrez, J. Mart \' n-Roca, V. Niggel, V. Carrasco-Fadanelli, I. Buttinoni, I. Pagonabarraga, L. Isa and C. Valeriani, Nanoscale, 2024, 16, 2444--2451

  15. [23]

    Kr \"u ger, C

    C. Kr \"u ger, C. Bahr, S. Herminghaus and C. C. Maass, The European Physical Journal E, 2016, 39, 64

  16. [24]

    Thutupalli, D

    S. Thutupalli, D. Geyer, R. Singh, R. Adhikari and H. A. Stone, Proceedings of the National Academy of Sciences, 2018, 115, 5403--5408

  17. [25]

    B. V. Hokmabad, A. Nishide, P. Ramesh, C. Krüger and C. C. Maass, Soft Matter, 2022, 18, 2731--2741

  18. [26]

    G. D. M. Carvajal, B. Taidi and M. Jarrahi, Algal Research, 2024, 77, 103350

  19. [27]

    Dervaux, M

    J. Dervaux, M. Capellazzi Resta and P. Brunet, Nature Physics, 2017, 13, 306--312

  20. [28]

    H. Chen, H. Zhang, T. Xu and J. Yu, ACS nano, 2021, 15, 15625--15644

  21. [29]

    Y. Fu, H. Yu, X. Zhang, P. Malgaretti, V. Kishore and W. Wang, Micromachines, 2022, 13, 295

  22. [30]

    R \"u hle, J

    F. R \"u hle, J. Blaschke, J.-T. Kuhr and H. Stark, New Journal of Physics, 2018, 20, 025003

  23. [31]

    Y. Ying, T. Jiang, S. Li, D. Nie and J. Lin, Physica Scripta, 2024, 99, 025304

  24. [32]

    D. Nie, Y. Ying, G. Guan, J. Lin and Z. Ouyang, Journal of Fluid Mechanics, 2023, 960, A31

  25. [33]

    G. Guan, J. Lin and D. Nie, Entropy, 2022, 24, 1564

  26. [34]

    Alarc \'o n and I

    F. Alarc \'o n and I. Pagonabarraga, Journal of Molecular Liquids, 2013, 185, 56--61

  27. [35]

    Vicsek, A

    T. Vicsek, A. Czir \'o k, E. Ben-Jacob, I. Cohen and O. Shochet, Physical review letters, 1995, 75, 1226

  28. [36]

    Chat \'e , F

    H. Chat \'e , F. Ginelli, G. Gr \'e goire, F. Peruani and F. Raynaud, The European Physical Journal B, 2008, 64, 451--456

  29. [37]

    Chat \'e , Annual Review of Condensed Matter Physics, 2020, 11, 189--212

    H. Chat \'e , Annual Review of Condensed Matter Physics, 2020, 11, 189--212

  30. [38]

    K \"u rsten and T

    R. K \"u rsten and T. Ihle, Physical Review Letters, 2020, 125, 188003

  31. [39]

    A. P. Solon, H. Chat \'e and J. Tailleur, Physical review letters, 2015, 114, 068101

  32. [40]

    Scagliarini and I

    A. Scagliarini and I. Pagonabarraga, Soft Matter, 2022, 18, 2407--2413

  33. [41]

    J.-T. Kuhr, J. Blaschke, F. R \"u hle and H. Stark, Soft Matter, 2017, 13, 7548--7555

  34. [42]

    R \"u hle and H

    F. R \"u hle and H. Stark, The European Physical Journal E, 2020, 43, 1--17

  35. [43]

    R \"u hle, A

    F. R \"u hle, A. W. Zantop and H. Stark, The European Physical Journal E, 2022, 45, 26

  36. [44]

    B. O. T. Maldonado, S. Pradeep, R. Ran, D. Jerolmack and P. E. Arratia, Journal of Fluid Mechanics, 2024, 988, A9

  37. [45]

    J.-T. Kuhr, F. R \"u hle and H. Stark, Soft Matter, 2019, 15, 5685--5694

  38. [46]

    Moncho-Jord \'a , A

    A. Moncho-Jord \'a , A. Louis and J. Padding, Physical review letters, 2010, 104, 068301

  39. [47]

    Lattuada, S

    E. Lattuada, S. Buzzaccaro and R. Piazza, Physical review letters, 2016, 116, 038301

  40. [48]

    Delfau, J

    J.-B. Delfau, J. Molina and M. Sano, Europhysics Letters, 2016, 114, 24001

  41. [49]

    B \'a rdfalvy, V

    D. B \'a rdfalvy, V. S kult \'e ty, C. Nardini, A. Morozov and J. Stenhammar, Communications Physics, 2024, 7, 93

  42. [50]

    Li and A

    G.-J. Li and A. M. Ardekani, Physical Review E, 2014, 90, 013010

  43. [51]

    Ishimoto and E

    K. Ishimoto and E. A. Gaffney, Physical Review E, 2013, 88, 062702

  44. [52]

    Schaar, A

    K. Schaar, A. Zöttl and H. Stark, Physical Review Letters, 2015, 115, 038101

  45. [53]

    Théry, C

    A. Théry, C. C. Maaß and E. Lauga, Royal Society Open Science, 2023, 10, 230223

  46. [54]

    Llopis and I

    I. Llopis and I. Pagonabarraga, Journal of Non-Newtonian Fluid Mechanics, 2010, 165, 946--952

  47. [55]

    Z. Shen, A. W \"u rger and J. S. Lintuvuori, The European Physical Journal E, 2018, 41, 1--9

  48. [56]

    Wu-Zhang, D

    B. Wu-Zhang, D. A. Fedosov and G. Gompper, Soft Matter, 2024

  49. [57]

    C. M. Barriuso Guti \'e rrez, J. Mart \' n-Roca, V. Bianco, I. Pagonabarraga and C. Valeriani, Frontiers in Physics, 2022, 10, 926609

  50. [58]

    Stukowski, Modelling and simulation in materials science and engineering, 2009, 18, 015012

    A. Stukowski, Modelling and simulation in materials science and engineering, 2009, 18, 015012

  51. [59]

    Plimpton, Journal of computational physics, 1995, 117, 1--19

    S. Plimpton, Journal of computational physics, 1995, 117, 1--19

  52. [60]

    R. D. Groot and P. B. Warren, The Journal of Chemical Physics, 1997, 107, 4423--4435

  53. [61]

    E. S. Boek and P. Van Der Schoot, International Journal of Modern Physics C, 1998, 09, 1307--1318

  54. [62]

    J. B. Gibson, K. Zhang, k. Chen, S. Chynoweth and C. W. Manke, Molecular Simulation, 1999, 23, 1--41

  55. [63]

    Whittle and E

    M. Whittle and E. Dickinson, Journal of Colloid and Interface Science, 2001, 242, 106--109

  56. [64]

    Whittle and K

    M. Whittle and K. P. Travis, The Journal of Chemical Physics, 2010, 132, 124906

  57. [65]

    E. I. Barcelos, S. Khani, A. Boromand, L. F. Vieira, J. A. Lee, J. Peet, M. F. Naccache and J. Maia, Computer Physics Communications, 2021, 258, 107618

  58. [66]

    Curk, The Journal of Chemical Physics, 2024, 160, 174115

    T. Curk, The Journal of Chemical Physics, 2024, 160, 174115

  59. [67]

    Lamura, G

    A. Lamura, G. Gompper, T. Ihle and D. M. Kroll, Europhysics Letters (EPL), 2001, 56, 319--325

  60. [68]

    Zöttl and H

    A. Zöttl and H. Stark, The European Physical Journal E, 2018, 41, 61

  61. [69]

    Lobaskin and B

    V. Lobaskin and B. Dünweg, New Journal of Physics, 2004, 6, 54

  62. [70]

    A. I. Campbell, S. J. Ebbens, P. Illien and R. Golestanian, Nature Communications, 2019, 10, 3952

  63. [71]

    M. J. Lighthill, Communications on pure and applied mathematics, 1952, 5, 109--118

  64. [72]

    J. R. Blake, Journal of Fluid Mechanics, 1971, 46, 199--208

  65. [73]

    Revenga, I

    M. Revenga, I. Zúñiga, P. Español and I. Pagonabarraga, International Journal of Modern Physics C, 1998, 09, 1319--1328

  66. [74]

    S. M. Willemsen, H. C. J. Hoefsloot and P. D. Iedema, International Journal of Modern Physics C, 2000, 11, 881--890

  67. [75]

    I. V. Pivkin and G. E. Karniadakis, Journal of Computational Physics, 2005, 207, 114--128

  68. [76]

    Mehboudi and M

    A. Mehboudi and M. S. Saidi, Scientia Iranica, 2011, 18, 1253--1260

  69. [77]

    S. K. Ranjith, B. S. V. Patnaik and S. Vedantam, Journal of Computational Physics, 2013, 232, 174--188

  70. [78]

    Z. Li, X. Bian, Y.-H. Tang and G. E. Karniadakis, Journal of Computational Physics, 2018, 355, 534--547

  71. [79]

    Y. Wang, J. She and Z. Zhou, Applied Mathematics and Mechanics, 2021, 42, 467--484

  72. [80]

    Ishikawa, M

    T. Ishikawa, M. P. Simmonds and T. J. Pedley, Journal of Fluid Mechanics, 2006, 568, 119

  73. [81]

    I. O. Götze and G. Gompper, Physical Review E, 2010, 82, 041921

  74. [82]

    S. E. Spagnolie and E. Lauga, Journal of Fluid Mechanics, 2012, 700, 105--147

  75. [83]

    J. S. Lintuvuori, A. T. Brown, K. Stratford and D. Marenduzzo, Soft Matter, 2016, 12, 7959--7968

  76. [84]

    Ishikawa, J

    T. Ishikawa, J. T. Locsei and T. J. Pedley, Journal of Fluid Mechanics, 2008, 615, 401--431

  77. [85]

    Halperin and D

    B. Halperin and D. R. Nelson, Physical Review Letters, 1978, 41, 121

  78. [86]

    D. R. Nelson and B. Halperin, Physical Review B, 1979, 19, 2457

  79. [87]

    W. B. Russel, D. A. Saville and W. R. Schowalter, Colloidal Dispersions, Cambridge University Press, 1989

  80. [88]

    Perkins and R

    G. Perkins and R. Jones, Physica A: Statistical Mechanics and its Applications, 1992, 189, 447--477

  81. [89]

    Happel and H

    J. Happel and H. Brenner, Low Reynolds number hydrodynamics: with special applications to particulate media , Springer Netherlands, Dordrecht, 1983, vol. 1

  82. [90]

    Rothschild , Nature, 1963, 198, 1221--1222

  83. [91]

    A. P. Berke, L. Turner, H. C. Berg and E. Lauga, Physical Review Letters, 2008, 101, 038102

  84. [92]

    Li and J

    G. Li and J. X. Tang, Physical Review Letters, 2009, 103, 078101

  85. [93]

    Molaei, M

    M. Molaei, M. Barry, R. Stocker and J. Sheng, Physical Review Letters, 2014, 113, 068103

  86. [94]

    Lauga and T

    E. Lauga and T. R. Powers, Reports on Progress in Physics, 2009, 72, 096601

  87. [95]

    Lauga, The Fluid Dynamics of Cell Motility , Cambridge University Press, 1st edn, 2020

    E. Lauga, The Fluid Dynamics of Cell Motility , Cambridge University Press, 1st edn, 2020

  88. [96]

    Palacci, C

    J. Palacci, C. Cottin-Bizonne, C. Ybert and L. Bocquet, Phys. Rev. Lett., 2010, 105, 088304

  89. [97]

    Ginot, I

    F. Ginot, I. Theurkauff, D. Levis, C. Ybert, L. Bocquet, L. Berthier and C. Cottin-Bizonne, Phys. Rev. X, 2015, 5, 011004

  90. [98]

    Enculescu and H

    M. Enculescu and H. Stark, Physical Review Letters, 2011, 107, 058301

  91. [99]

    Thutupalli, R

    S. Thutupalli, R. Seemann and S. Herminghaus, New Journal of Physics, 2011, 13, 073021

  92. [100]

    Nishiguchi and M

    D. Nishiguchi and M. Sano, Physical Review E, 2015, 92, 052309

  93. [101]

    Deseigne, O

    J. Deseigne, O. Dauchot and H. Chaté, Physical Review Letters, 2010, 105, 098001

  94. [102]

    Oyama, J

    N. Oyama, J. J. Molina and R. Yamamoto, Physical Review E, 2016, 93, 043114

  95. [103]

    A. A. Evans, T. Ishikawa, T. Yamaguchi and E. Lauga, Physics of Fluids, 2011, 23, 111702

  96. [104]

    Zöttl and H

    A. Zöttl and H. Stark, Physical Review Letters, 2014, 112, 118101

  97. [105]

    u rsten, R \

    Z. Ouyang, J. Lin and X. Ku, Rheologica Acta, 2018, 57, 655--671 mcitethebibliography GW.bib0000664000000000000000000020712214717210745010565 0ustar rootroot@article halperin1978theory, title= Theory of two-dimensional melting , author= Halperin, BI and Nelson, David R , journ...

Pith tools

Reviewed August 12, 2026 · model on record in the stance chip above.