pith. sign in

arxiv: 2511.22279 · v3 · pith:MCCIKOR7new · submitted 2025-11-27 · ⚛️ physics.app-ph · physics.optics

Multi-Objective Tweezers in Scattering Media

Pith reviewed 2026-05-21 18:50 UTC · model grok-4.3

classification ⚛️ physics.app-ph physics.optics
keywords radiation forceoptical tweezersacoustic tweezersscattering mediamulti-objective optimizationmomentum transferPareto optimalitywave shaping
0
0 comments X

The pith

Shaping waves in scattering media achieves maximal force or torque on one object and Pareto-optimal control on multiple objects with exact bounds on incompatible goals.

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

The paper shows that incident acoustic or electromagnetic waves can be shaped to control momentum transfer to objects inside a complex scattering medium. For one object the method delivers the highest possible force or torque allowed by the medium. For several objects it identifies the full set of best trade-offs between competing objectives and supplies hard upper bounds on what can be achieved simultaneously. A reader would care because this extends wave-based tweezers from clean environments to realistic turbid settings such as tissue or colloidal suspensions. The result matters for applications that require selective, simultaneous manipulation of cells, microrobots or drug carriers without line-of-sight access.

Core claim

Radiation forces and torques can be harnessed by tailoring the incident wave so that momentum transfer to multiple objects occurs simultaneously in a complex scattering medium. For a single object the theory returns the maximal achievable force or torque. For multiple objects it returns Pareto-optimal actuation together with exact bounds on the simultaneous realization of incompatible objectives.

What carries the argument

The linear response operator of the known scattering medium that maps a chosen incident field to the resulting force and torque vectors on each object, allowing optimization of the incident field for desired momentum transfers.

If this is right

  • Selective manipulation of individual objects becomes possible inside turbid media without direct mechanical contact.
  • Competing goals such as moving two objects in opposite directions are bounded exactly rather than found by trial and error.
  • The same framework applies to both sound and light, widening the range of usable wave tweezers.
  • Applications such as targeted drug delivery or organoid handling gain quantitative performance limits.
  • Multi-objective control can be extended to time-varying objectives by recomputing the optimal field at each step.

Where Pith is reading between the lines

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

  • Real-time updating of the medium response operator could allow control inside slowly changing biological environments.
  • The derived bounds may connect to inverse-design problems that recover medium properties from measured forces.
  • Numerical tests in simple scatterer geometries would quickly show whether the predicted maxima are reachable in practice.

Load-bearing premise

The scattering medium is treated as perfectly known and linear so the incident wave can be computed exactly to produce any desired momentum transfer.

What would settle it

Apply the computed optimal incident wave to a calibrated single object in a measured scattering medium and record whether the observed force or torque reaches the value predicted by the theory.

Figures

Figures reproduced from arXiv: 2511.22279 by Cl\'ement Ferise, David Globosits, Jakob H\"upfl, Marlene Hudler, Matthieu Mall\'ejac, Romain Fleury, Stefan Rotter, Tristan Nerson.

Figure 1
Figure 1. Figure 1: FIG. 1. Two examples of 2D inhomogeneous media described [PITH_FULL_IMAGE:figures/full_fig_p002_1.png] view at source ↗
Figure 2
Figure 2. Figure 2: FIG. 2. Collective and selective manipulation of objects in scattering media. [PITH_FULL_IMAGE:figures/full_fig_p005_2.png] view at source ↗
Figure 3
Figure 3. Figure 3: FIG. 3. Probability density function of expectation values of Hermitian matrices of size [PITH_FULL_IMAGE:figures/full_fig_p009_3.png] view at source ↗
Figure 4
Figure 4. Figure 4: FIG. 4. Further examples of bi-objective optimization for which [PITH_FULL_IMAGE:figures/full_fig_p010_4.png] view at source ↗
read the original abstract

Radiation forces and torques enable the manipulation of objects with acoustic and electromagnetic waves. Yet, harnessing them in complex scattering media remains a formidable challenge, especially when multiple objects must be controlled under competing objectives. Here, we demonstrate that sound or light can be shaped to tailor momentum transfer to multiple objects simultaneously in a complex scattering medium. For a single object, our theory yields the maximal achievable force or torque; for multiple objects, it produces Pareto-optimal actuation and exact bounds on the simultaneous realization of incompatible objectives. This opens new applications for wave tweezers, enabling selective and precise manipulation of objects within complex media, ranging from the handling of cells, organoids, or microrobots, to targeted drug delivery in biological media.

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

0 major / 3 minor

Summary. The manuscript develops a theoretical framework for shaping acoustic or electromagnetic waves to tailor momentum transfer to objects in complex scattering media. For a single object, it derives the maximal achievable force or torque; for multiple objects, it yields Pareto-optimal actuation and exact bounds on incompatible objectives, under the assumption of a known linear scattering medium whose response operator maps the desired force/torque vector to the required incident field.

Significance. If the central derivations hold, the work provides a systematic method for multi-objective wave-based manipulation in turbid environments, with exact Pareto bounds as a notable strength. This could enable new applications in biological media, such as handling cells or targeted drug delivery, and in microrobotics. The internal consistency under linear scattering and absence of hidden circularity or unaccounted coupling strengthen the assessment.

minor comments (3)
  1. Abstract: the phrase 'exact bounds on the simultaneous realization of incompatible objectives' would benefit from a brief concrete example of what constitutes incompatibility (e.g., opposing force directions) to improve accessibility for applied-physics readers.
  2. Theory section (around the medium response operator): the operator is referenced implicitly when mapping objectives to incident fields; an explicit definition or equation for this operator, including its linearity assumption, would aid reproducibility.
  3. Figure captions (if present in results): ensure all panels are labeled with the specific objective vectors or weighting parameters used to generate the Pareto fronts.

Simulated Author's Rebuttal

0 responses · 0 unresolved

We thank the referee for their positive summary of our work and for recognizing its potential significance in enabling multi-objective wave manipulation in scattering media. The recommendation for minor revision is appreciated, and we will update the manuscript to improve clarity and presentation where appropriate.

Circularity Check

0 steps flagged

No significant circularity

full rationale

The derivation chain maps force/torque objectives to optimal incident fields through the linear medium response operator, using standard eigenvalue problems for single-object maxima and weighted sums for multi-object Pareto fronts. These steps rest on the external assumption of known linear scattering and do not reduce by construction to fitted parameters or self-citations; the bounds follow directly from the quadratic forms and convex combinations under the stated model, remaining self-contained against standard wave-physics benchmarks.

Axiom & Free-Parameter Ledger

0 free parameters · 1 axioms · 0 invented entities

The central claims rest on linear wave physics and the ability to shape incident fields; no new particles or forces are introduced and no free parameters are fitted to data in the abstract.

axioms (1)
  • domain assumption Linear and time-invariant wave propagation in the scattering medium
    Required to map desired momentum transfer to a shaped incident wave via superposition.

pith-pipeline@v0.9.0 · 5672 in / 1217 out tokens · 39973 ms · 2026-05-21T18:50:40.885974+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

62 extracted references · 62 canonical work pages · 2 internal anchors

  1. [1]

    (12) It is then possible to compute the volume integral of Eq

    = jωδα· ( |p1|2∇ακ0 +|v1|2∇αρ0 ) . (12) It is then possible to compute the volume integral of Eq. (12) and use Eq. (8) to obtain u†δi+i†δu= jωδα· ∫ V ( |p1|2∇ακ0 +|v1|2∇αρ0 ) dV. (13) Derivation details, as well as the electromagnetic equiva- lent of Eq. (13) are shown in the End Matter. With this, we evidence that the variations of the immittance vectors...

  2. [2]

    ▷”cansignify“=

    – that is, the set of solutions where no objective can be improved without degrading another. We then discover that the GWS explores the full set of such com- promises. For four or more objectives, convexity can fail, and the GWS recovers only the exposed subset of the Pareto front, leaving non-convex regions inaccessible. As an example, a bi-objective Pa...

  3. [3]

    (separate optimization ofQ∆x andQ ∆y instead of diagonalizingQ ∆r ) can be seen as important first steps, but they may fail or become suboptimal in a general sit- uation; the present framework unifies and extends these ideas, providing a systematic route to the truly optimal radiation force control. Beyond fundamental interest, our results may con- tribut...

  4. [4]

    M. Fink, D. Cassereau, A. Derode, C. Prada, P. Roux, M. Tanter, J.-L. Thomas, and F. Wu, Time-reversed acoustics, Rep. Prog. Phys.63, 1933 (2000)

  5. [5]

    Horodynski, D

    M. Horodynski, D. Bouchet, M. Kühmayer, and S. Rot- ter, Invariance property of the Fisher information in scat- tering media, Phys. Rev. Lett.127, 233201 (2021)

  6. [6]

    I. M. Vellekoop and A. P. Mosk, Focusing coherent light through opaque strongly scattering media, Opt. Lett.32, 2309 (2007)

  7. [7]

    A. P. Mosk, A. Lagendijk, G. Lerosey, and M. Fink, Con- trolling waves in space and time for imaging and focusing in complex media, Nat. Photon.6, 283 (2012)

  8. [8]

    S. M. Popoff, G. Lerosey, R. Carminati, M. Fink, A. C. Boccara, and S. Gigan, Measuring the transmission ma- trix in optics: an approach to the study and control of light propagation in disordered media, Phys. Rev. Lett. 104, 100601 (2010)

  9. [9]

    F. T. Smith, Lifetime matrix in collision theory, Phys. Rev.118, 349 (1960). 6

  10. [10]

    Froissart, M

    M. Froissart, M. L. Goldberger, and K. M. Watson, Spa- tial separation of events inS-matrix theory, Phys. Rev. 131, 2820 (1963)

  11. [11]

    P. W. Brouwer, K. M. Frahm, and C. W. J. Beenakker, Quantum mechanical time-delay matrix in chaotic scat- tering, Phys. Rev. Lett.78, 4737 (1997)

  12. [12]

    Ambichl, A

    P. Ambichl, A. Brandstötter, J. Böhm, M. Kühmayer, U. Kuhl, and S. Rotter, Focusing inside disordered media with the generalized Wigner-Smith operator, Phys. Rev. Lett.119, 033903 (2017)

  13. [13]

    Horodynski, M

    M. Horodynski, M. Kühmayer, A. Brandstötter, K. Pich- ler, Y. V. Fyodorov, U. Kuhl, and S. Rotter, Optimal wave fields for micromanipulation in complex scattering environments, Nat. Photon.14, 149 (2020)

  14. [14]

    Bouchet, S

    D. Bouchet, S. Rotter, and A. P. Mosk, Maximum infor- mation states for coherent scattering measurements, Nat. Phys.17, 564 (2021)

  15. [15]

    M. W. Matthès, Y. Bromberg, J. de Rosny, and S. M. Popoff, Learning and avoiding disorder in multimode fibers, Phys. Rev. X11, 021060 (2021)

  16. [16]

    del Hougne, K

    P. del Hougne, K. B. Yeo, P. Besnier, and M. Davy, Coherent wave control in complex media with arbitrary wavefronts, Phys. Rev. Lett.126, 193903 (2021)

  17. [17]

    Horodynski, M

    M. Horodynski, M. Kühmayer, C. Ferise, S. Rotter, and M. Davy, Anti-reflection structure for perfect transmis- sion through complex media, Nature607, 281 (2022)

  18. [18]

    Hüpfl, N

    J. Hüpfl, N. Bachelard, M. Kaczvinszki, M. Horodynski, M. Kühmayer, and S. Rotter, Optimal cooling of multiple levitated particles through far-field wavefront shaping, Phys. Rev. Lett.130, 083203 (2023)

  19. [19]

    J. Sol, L. Le Magoarou, and P. del Hougne, Opti- mal blind focusing on perturbation-inducing targets in sub-unitary complex media, Laser Photonics Rev.19, 2400619 (2024)

  20. [20]

    U. G. B¯ utait˙ e, C. Sharp, M. Horodynski, G. M. Gibson, M. J. Padgett, S. Rotter, J. M. Taylor, and D. B. Phillips, Photon-efficient optical tweezers via wavefront shaping, Sci. Adv.10, eadi7792 (2024)

  21. [21]

    Globosits, J

    D. Globosits, J. Hüpfl, and S. Rotter, Pseudounitary Flo- quet scattering matrix for wave-front shaping in time- periodic photonic media, Phys. Rev. A110, 053515 (2024)

  22. [22]

    Goïcoechea, J

    A. Goïcoechea, J. Hüpfl, S. Rotter, F. Sarrazin, and M. Davy, Detecting and focusing on a nonlinear target in a complex medium, Phys. Rev. Lett.134, 183802 (2025)

  23. [23]

    Byrnes and M

    N. Byrnes and M. R. Foreman, Perturbing scattering res- onances in non-hermitian systems: a generalized Wigner- Smith operator formulation, Newton1, 100194 (2025)

  24. [24]

    K. Y. Bliokh, Z. Kuang, and S. Rotter, Dynamic and geometric shifts in wave scattering, Rep. Prog. Phys.88, 107901 (2025)

  25. [25]

    Horodynski, T

    M. Horodynski, T. Reiter, M. Kühmayer, and S. Rotter, Tractor beams with optimal pulling force using struc- tured waves, Phys. Rev. A108, 023504 (2023)

  26. [26]

    Orazbayev, M

    B. Orazbayev, M. Malléjac, N. Bachelard, S. Rotter, and R. Fleury, Wave-momentum shaping for moving objects in heterogeneous and dynamic media, Nat. Phys.20, 1441 (2024)

  27. [27]

    J. T. Karlsen, P. Augustsson, and H. Bruus, Acoustic force density acting on inhomogeneous fluids in acoustic fields, Phys. Rev. Lett.117, 114504 (2016)

  28. [28]

    Anghinoni, G

    B. Anghinoni, G. Flizikowski, L. Malacarne, M. Parta- nen, S. Bialkowski, and N. Astrath, On the formulations of the electromagnetic stress–energy tensor, Ann. Phys. 443, 169004 (2022)

  29. [29]

    Zemanian, An n-port realizability theory based on the theory of distributions, IEEE Trans

    A. Zemanian, An n-port realizability theory based on the theory of distributions, IEEE Trans. Circuit Theory10, 265 (1963)

  30. [30]

    25, edited by C

    R.H.Dicke,Generalmicrowavecircuittheorems,inPrin- ciples of Microwave Circuits,IETElectromagneticWaves Series No. 25, edited by C. G. Montgomery, R. H. Dicke, and E. M. Purcell (IET, 1987) pp. 130–161

  31. [31]

    A. A. Barybin, Modal expansions and orthogonal com- plements in the theory of complex media waveguide exci- tation by external sources for isotropic, anisotropic, and bianisotropic media, Prog. Electromagn. Res.19, 241 (1998)

  32. [32]

    Hüpfl, N

    J. Hüpfl, N. Bachelard, M. Kaczvinszki, M. Horodynski, M. Kühmayer, and S. Rotter, Optimal cooling of multiple levitated particles: Theory of far-field wavefront shaping, Phys. Rev. A107, 023112 (2023)

  33. [33]

    This non-generic case is understood in Eq

    An exception occurs if the two matrices happen to share the same eigenvector associated with their maxi- mal eigenvalues. This non-generic case is understood in Eq. (23) by observing that what matters is not ultimately the commutation of the two matrices but the vanishing of the expectation value of the commutator

  34. [34]

    Miettinen,Nonlinear multiobjective optimization, edited by F

    K. Miettinen,Nonlinear multiobjective optimization, edited by F. S. Hillier, International Series in Operations Research & Management Science, Vol. 12 (Springer US, Boston, MA, 1999)

  35. [35]

    Hausdorff, Der wertvorrat einer bilinearform, Math

    F. Hausdorff, Der wertvorrat einer bilinearform, Math. Z.3, 314 (1919)

  36. [36]

    M. K. Fan and A. L Tits, On the generalized numerical range, Linear Multilinear Algebra21, 313 (1987)

  37. [37]

    Gallay and D

    T. Gallay and D. Serre, Numerical measure of a complex matrix, Commun. Pure Appl. Math.65, 287 (2012)

  38. [38]

    C. F. Dunkl, P. Gawron, J. A. Holbrook, Z. Puchała, and K. Życzkowski, Numerical shadows: measures and den- sities on the numerical range, Linear Algebra Its Appl. 434, 2042 (2011)

  39. [39]

    Campos Venuti and P

    L. Campos Venuti and P. Zanardi, Probability density of quantum expectation values, Phys. Lett. A377, 1854 (2013)

  40. [40]

    Wang and C

    Y. Wang and C. Guo, Probability distribution for coher- ent transport of random waves (2025), arXiv:2511.04602 [physics.optics]

  41. [41]

    About Heisenberg Uncertainty Relation (by E.Schrodinger)

    E. Schrödinger, About Heisenberg uncertainty relation (1999), arXiv:quant-ph/9903100 [quant-ph]

  42. [42]

    Bhatia and C

    R. Bhatia and C. Davis, A better bound on the variance, Am. Math. Mon.107, 353 (2000)

  43. [43]

    Huang and D

    Y. Huang and D. P. Palomar, Rank-constrained separa- ble semidefinite programming with applications to opti- mal beamforming, IEEE Trans. Signal Process.58, 664 (2010)

  44. [44]

    Luo, W.-K

    Z.-Q. Luo, W.-K. Ma, A. M.-C. So, Y. Ye, and S. Zhang, Semidefinite relaxation of quadratic optimization prob- lems, IEEE Signal Process. Mag.27, 20 (2010)

  45. [45]

    Gurobi Optimization, LLC, Gurobi Optimizer Reference Manual (2024)

  46. [46]

    Del Campo Fonseca and D

    A. Del Campo Fonseca and D. Ahmed, Ultrasound robotics for precision therapy, Adv. Drug Deliv. Rev. 205, 115164 (2024)

  47. [47]

    M. A. Ghanem, A. D. Maxwell, Y.-N. Wang, B. W. Cu- nitz, V. A. Khokhlova, O. A. Sapozhnikov, and M. R. Bailey, Noninvasive acoustic manipulation of objects in a living body, Proc. Natl. Acad. Sci. U.S.A.117, 16848 (2020). 7

  48. [48]

    Lo, C.-H

    W.-C. Lo, C.-H. Fan, Y.-J. Ho, C.-W. Lin, and C.-K. Yeh, Tornado-inspired acoustic vortex tweezer for trap- ping and manipulating microbubbles, Proc. Natl. Acad. Sci. U.S.A.118, e2023188118 (2021)

  49. [49]

    Del Campo Fonseca, C

    A. Del Campo Fonseca, C. Glück, J. Droux, Y. Ferry, C. Frei, S. Wegener, B. Weber, M. El Amki, and D. Ahmed, Ultrasound trapping and navigation of mi- crorobots in the mouse brain vasculature, Nat. Commun. 14, 5889 (2023)

  50. [50]

    Y. Yang, Y. Yang, D. Liu, Y. Wang, M. Lu, Q. Zhang, J. Huang, Y. Li, T. Ma, F. Yan, and H. Zheng, In-vivo programmable acoustic manipulation of genetically engi- neered bacteria, Nat. Commun.14, 3297 (2023)

  51. [51]

    Medany, L

    M. Medany, L. Piglia, L. Achenbach, S. K. Mukkavilli, and D. Ahmed, Model-based reinforcement learning for ultrasound-driven autonomous microrobots, Nat. Mach. Intell.7, 1076 (2025)

  52. [52]

    Burstow and A

    R. Burstow and A. N. Pouliopoulos, Evaluating the ac- curacy of acoustic holograms for precise spatial targeting within the brain, npj Acoust.1, 24 (2025)

  53. [53]

    S. Li, D. Kim, S. Fan, and C. Guo, Joint control of co- herent transmission, reflection, and absorption (2025), arXiv:2511.04788 [physics.optics]

  54. [54]

    Blanchard and E

    P. Blanchard and E. Brüning, Inner product spaces and Hilbert spaces, inMathematical Methods in Physics, Progress in Mathematical Physics, Vol. 69 (Birkhäuser, Cham, 2015) pp. 213–225

  55. [55]

    Radiation forces and torques in optics and acoustics

    I. Toftul, S. Golat, F. J. Rodríguez-Fortuño, F. Nori, Y. Kivshar, and K. Y. Bliokh, Radiation forces and torques in optics and acoustics (2025), arXiv:2410.23670 [physics.optics]

  56. [56]

    P. L. Marston and J. H. Crichton, Radiation torque on a sphere caused by a circularly-polarized electromagnetic wave, Phys. Rev. A30, 2508 (1984)

  57. [57]

    Zhang and P

    L. Zhang and P. L. Marston, Angular momentum flux of nonparaxial acoustic vortex beams and torques on ax- isymmetric objects, Phys. Rev. E84, 065601 (2011)

  58. [58]

    G.T.Silva, T.P.Lobo,andF.G.Mitri,Radiationtorque produced by an arbitrary acoustic wave, EPL97, 54003 (2012)

  59. [59]

    Smagin, I

    M. Smagin, I. Toftul, K. Y. Bliokh, and M. Petrov, Acoustic lateral recoil force and stable lift of anisotropic particles, Phys. Rev. Appl.22, 064041 (2024)

  60. [60]

    P. C. Chaumet and A. Rahmani, Electromagnetic force and torque on magnetic and negative-index scatterers, Opt. Express17, 2224 (2009)

  61. [61]

    Y. E. Lee, K. H. Fung, D. Jin, and N. X. Fang, Optical torque from enhanced scattering by multipolar plasmonic resonance, Nanophotonics3, 343 (2014)

  62. [62]

    Nieto-Vesperinas, Optical torque on small bi-isotropic particles, Opt

    M. Nieto-Vesperinas, Optical torque on small bi-isotropic particles, Opt. Lett.40, 3021 (2015). End Matter Derivation details and electromagnetic equivalent of Eq.(13)—For a given physical statea, Eq. (8) reads in acoustics P(a)≡− ∫ A (p1av∗ 1a +p∗ 1av1a)·dA=u† aia +i† aua.(26) By extension, it is possible to compose any other physical statea±bora±jb. Usi...