Membrane-based Acoustic Microrobots

Cemal Polat Avdar; Fatih Kocabas; Prithvi Venkatesh; Yunus Alapan

arxiv: 2606.21047 · v1 · pith:FXQWMYJ6new · submitted 2026-06-19 · 💻 cs.RO

Membrane-based Acoustic Microrobots

Fatih Kocabas , Cemal Polat Avdar , Prithvi Venkatesh , Yunus Alapan This is my paper

Pith reviewed 2026-06-26 14:39 UTC · model grok-4.3

classification 💻 cs.RO

keywords acoustic microrobotsPDMS membranemicrostreaminggas diffusionmagnetic controllong-term operationtargeted drug delivery

0 comments

The pith

A thin PDMS membrane over microcavities blocks gas diffusion so acoustic microrobots maintain stable streaming and propulsion for more than 24 hours.

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

The paper tries to establish that conventional acoustic microrobots lose performance quickly because gas dissolves out of trapped microbubbles and shifts their resonance. It replaces the open cavity design with a thin flexible PDMS membrane bonded over the cavities, which physically stops gas escape while still transmitting acoustic actuation to produce microstreaming. If the approach works, the robots can run continuously at high voltages without rapid failure, supporting longer tasks in drug delivery or minimally invasive procedures. The design also incorporates magnetic particles for steering and scales to roughly 100 micrometers.

Core claim

Bonding a thin flexible PDMS membrane over confined microcavities physically prevents gas diffusion in acoustic microrobots. This maintains stable resonance and produces consistent microstreaming and propulsion for over 24 hours of continuous operation even at high actuation voltages. Embedding magnetic microparticles in the body permits directional control with 2 mT external fields, and the overall architecture scales down to approximately 100 micrometers.

What carries the argument

Thin flexible PDMS membrane bonded over confined microcavities that seals against gas diffusion while permitting acoustic microstreaming.

If this is right

Consistent streaming and propulsion continue for over 24 hours of continuous operation at high voltages.
Actuators function as microswimmers with directional control from low-intensity 2 mT external magnetic fields.
The architecture scales down to approximately 100 micrometers while retaining function.
The sealed design provides a framework for high-endurance acoustic microactuators and microrobots suited to long-term tasks.

Where Pith is reading between the lines

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

The sealing method could be tested in other fluid-filled microsystems that lose performance from gas leakage.
Embedding drug carriers inside the same body might allow sustained release during multi-hour missions without resonance drift.
Further reduction below 100 micrometers could be checked to see whether membrane thickness still permits effective streaming.

Load-bearing premise

The PDMS membrane remains intact, securely bonded, and does not degrade, detach, or change acoustic properties during prolonged high-voltage operation.

What would settle it

A test in which streaming velocity drops or resonance shifts within 24 hours of continuous high-voltage actuation because the membrane fails or gas escapes would falsify the stability claim.

Figures

Figures reproduced from arXiv: 2606.21047 by Cemal Polat Avdar, Fatih Kocabas, Prithvi Venkatesh, Yunus Alapan.

read the original abstract

Acoustic microrobots have emerged as a promising frontier for targeted drug delivery and minimally invasive medicine due to their high-power density and biocompatibility. Despite wide-ranging designs, conventional acoustic microrobots mostly rely on air microbubbles trapped within confined microcavities within the robot body, which suffer from limited operational longevity due to rapid gas dissolution and resultant shifts in resonance frequency. In this paper, we propose a robust, membrane-based acoustic microrobot that overcomes these limitations by employing a thin flexible Polydimethylsiloxane (PDMS) membrane bonded over confined microcavities for microstreaming. The introduced design physically prevents gas diffusion, ensuring stable performance over extended periods at high actuation voltages. We systematically characterized the membrane-based acoustic actuator longevity, demonstrating consistent streaming and propulsion for over 24 hours of continuous operation. In addition, by embedding magnetic microparticles into the structural body, these actuators were successfully employed as microswimmers with directional control using low-intensity (2 mT) external magnetic fields. Finally, we demonstrate the scalability of the proposed design architecture down to ~100 um. This membrane-based approach establishes a reliable framework for the development of high-endurance acoustic microactuators and microrobots capable of performing long-term tasks.

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.

Desk Editor's Note private letter to a colleague

The membrane over microcavities is a simple way to extend acoustic microrobot runtime to 24 hours, but the claim that it physically blocks gas diffusion does not hold up without direct evidence given how permeable PDMS is.

read the letter

The main takeaway is that sealing the air cavities with a thin PDMS membrane lets the acoustic streaming and propulsion stay stable for over 24 hours of continuous use, which is longer than typical open-bubble designs. They also embed magnetic particles for steering at 2 mT and show the approach scales to about 100 microns.

That longevity result is the concrete part worth noting. If the fabrication is repeatable, groups working on acoustic actuators for drug delivery or medical microrobots could try the same sealing step and get more operating time.

The weak point is the stated mechanism. The abstract says the membrane physically prevents gas diffusion. PDMS has high gas permeability though, so molecules can still cross the membrane bulk even with bonded edges. No mention of membrane thickness, calculated leak rates, or direct checks like internal pressure or volume measurements over time. The observed stability could come from membrane flex instead of sealed gas. Without those data the explanation sits on an assumption that does not match known material properties.

This is the sort of paper that fits a microrobotics or acoustic propulsion reading group. Readers already building bubble-based devices would get the fabrication details and the runtime numbers to test against their own setups.

I would send it to peer review. The experimental claim is straightforward to check and the design is practical enough that referees can focus on whether the gas retention actually works as described.

Referee Report

1 major / 1 minor

Summary. The manuscript proposes a membrane-based acoustic microrobot that bonds a thin flexible PDMS membrane over confined microcavities to trap air for microstreaming. It claims this design physically prevents gas diffusion, enabling consistent streaming and propulsion for over 24 hours of continuous operation at high actuation voltages, with additional demonstrations of magnetic directional control using embedded microparticles under 2 mT fields and scalability down to ~100 μm.

Significance. If supported by direct evidence that the membrane prevents diffusion and sustains resonance without gas loss, the approach would address a key limitation in acoustic microrobotics and support longer-duration tasks in biomedical applications.

major comments (1)

[Abstract] Abstract: The central claim that the PDMS membrane 'physically prevents gas diffusion' is load-bearing for the 24-hour stability result, yet the known high gas permeability of PDMS (oxygen permeability ~600 barrer) permits diffusion through the membrane bulk regardless of edge bonding. No membrane thickness, permeation rate calculation, or time-series measurement of internal gas pressure/volume is referenced to rule out this mechanism.

minor comments (1)

[Abstract] The abstract states that 'systematic characterization' of longevity was performed, but provides no details on sample size, voltage levels, error bars, or controls for alternative explanations of streaming stability (e.g., membrane compliance).

Simulated Author's Rebuttal

1 responses · 0 unresolved

We thank the referee for their constructive comment on the abstract's central claim. We address the concern point-by-point below and will revise the manuscript accordingly.

read point-by-point responses

Referee: [Abstract] Abstract: The central claim that the PDMS membrane 'physically prevents gas diffusion' is load-bearing for the 24-hour stability result, yet the known high gas permeability of PDMS (oxygen permeability ~600 barrer) permits diffusion through the membrane bulk regardless of edge bonding. No membrane thickness, permeation rate calculation, or time-series measurement of internal gas pressure/volume is referenced to rule out this mechanism.

Authors: We agree that the phrasing 'physically prevents gas diffusion' is imprecise and not fully supported. PDMS is permeable, so diffusion through the bulk membrane cannot be ruled out by edge bonding alone. The design seals the microcavity opening with a thin membrane to reduce direct gas escape and maintain air trapping for microstreaming, which empirically yields >24 h stability in our tests, but we provide no permeation calculations, pressure/volume time-series data, or explicit thickness values to quantify the contribution of reduced diffusion versus other factors (e.g., geometry or actuation conditions). We will revise the abstract to remove the load-bearing claim, replace it with a description of the sealed-cavity architecture enabling prolonged operation, and add the membrane thickness to the methods. We will also note the empirical longevity result without asserting mechanistic prevention of diffusion. revision: yes

Circularity Check

0 steps flagged

No circularity: purely experimental design and characterization

full rationale

The paper is an experimental report describing fabrication, bonding of a PDMS membrane over microcavities, and direct measurements of streaming stability over 24 hours. No equations, derivations, fitted parameters, or mathematical predictions appear in the abstract or described content. Claims rest on physical demonstration rather than any derivation chain. No self-citations, uniqueness theorems, or ansatzes are invoked. The central claim of prevented gas diffusion is an empirical observation from longevity tests, not a reduction to prior inputs by construction.

Axiom & Free-Parameter Ledger

0 free parameters · 2 axioms · 0 invented entities

The central claim rests on standard microfabrication assumptions rather than new mathematical constructs or invented entities.

axioms (2)

domain assumption PDMS membrane can be bonded over microcavities to form a durable gas-tight seal without compromising acoustic resonance
Required for the physical prevention of gas diffusion claimed in the abstract.
domain assumption Embedding magnetic microparticles does not interfere with acoustic streaming performance
Needed for the dual acoustic-magnetic functionality described.

pith-pipeline@v0.9.1-grok · 5757 in / 1186 out tokens · 34068 ms · 2026-06-26T14:39:45.098755+00:00 · methodology

discussion (0)

Reference graph

Works this paper leans on

25 extracted references · 24 canonical work pages

[1]

Rotational manipulation of single cells and organisms using acoustic waves,

D. Ahmed et al., “Rotational manipulation of single cells and organisms using acoustic waves,” Nat. Commun., vol. 7, no. 1, p. 11085, Mar. 2016, doi: 10.1038/ncomms11085

work page doi:10.1038/ncomms11085 2016
[2]

3D steerable, acoustically powered microswimmers for single-particle manipulation,

L. Ren et al., “3D steerable, acoustically powered microswimmers for single-particle manipulation,” Sci. Adv., vol. 5, no. 10, p. eaax3084, Oct. 2019, doi: 10.1126/sciadv.aax3084

work page doi:10.1126/sciadv.aax3084 2019
[3]

Microporous Magnetic Soft Materials with Programmable Locomotion and On-Demand Liquid Cargo Release,

Y. Zhou, F. Kocabas, and Y. Alapan, “Microporous Magnetic Soft Materials with Programmable Locomotion and On-Demand Liquid Cargo Release,” in 2025 International Conference on Manipulation, Automation and Robotics at Small Scales (MARSS), West Lafayette, IN, USA: IEEE, Jul. 2025, pp. 01–06. doi: 10.1109/MARSS65887.2025.11072793

work page doi:10.1109/marss65887.2025.11072793 2025
[4]

Magnetically steerable bacterial microrobots moving in 3D biological matrices for stimuli-responsive cargo delivery,

M. B. Akolpoglu et al., “Magnetically steerable bacterial microrobots moving in 3D biological matrices for stimuli-responsive cargo delivery,” Sci. Adv., vol. 8, no. 28, p. eabo6163, Jul. 2022, doi: 10.1126/sciadv.abo6163

work page doi:10.1126/sciadv.abo6163 2022
[5]

Microrobotics and Microorganisms: Biohybrid Autonomous Cellular Robots,

Y. Alapan, O. Yasa, B. Yigit, I. C. Yasa, P. Erkoc, and M. Sitti, “Microrobotics and Microorganisms: Biohybrid Autonomous Cellular Robots,” Annu. Rev. Control Robot. Auton. Syst., vol. 2, no. 1, pp. 205–230, May 2019, doi: 10.1146/annurev-control-053018- 023803

work page doi:10.1146/annurev-control-053018- 2019
[6]

Mobile Microrobots for Active Therapeutic Delivery,

P. Erkoc, I. C. Yasa, H. Ceylan, O. Yasa, Y. Alapan, and M. Sitti, “Mobile Microrobots for Active Therapeutic Delivery,” Adv. Ther., vol. 2, no. 1, p. 1800064, Jan. 2019, doi: 10.1002/adtp.201800064

work page doi:10.1002/adtp.201800064 2019
[7]

Shape- encoded dynamic assembly of mobile micromachines,

Y. Alapan, B. Yigit, O. Beker, A. F. Demirörs, and M. Sitti, “Shape- encoded dynamic assembly of mobile micromachines,” Nat. Mater., vol. 18, no. 11, pp. 1244–1251, Nov. 2019, doi: 10.1038/s41563- 019-0407-3

work page doi:10.1038/s41563- 2019
[8]

Zhang, N

F. Kocabas, O. Oguztuzun, Y. Zhou, and Y. Alapan, “Magnetic Programming of Soft Materials Using Digitally Processed Laser Heating,” in 2025 IEEE International Conference on Robotics and Automation (ICRA), Atlanta, GA, USA: IEEE, May 2025, pp. 15350–15355. doi: 10.1109/ICRA55743.2025.11127804

work page doi:10.1109/icra55743.2025.11127804 2025
[9]

Multifunctional biohybrid magnetite microrobots for imaging-guided therapy,

X. Yan et al., “Multifunctional biohybrid magnetite microrobots for imaging-guided therapy,” Sci. Robot., vol. 2, no. 12, p. eaaq1155, Nov. 2017, doi: 10.1126/scirobotics.aaq1155

work page doi:10.1126/scirobotics.aaq1155 2017
[10]

Actuation of Mobile Microbots: A Review,

H. Hussein et al., “Actuation of Mobile Microbots: A Review,” Adv. Intell. Syst., vol. 5, no. 9, p. 2300168, Sep. 2023, doi: 10.1002/aisy.202300168

work page doi:10.1002/aisy.202300168 2023
[11]

Acoustically Powered Nano- and Microswimmers: From Individual to Collective Behavior,

J. M. McNeill and T. E. Mallouk, “Acoustically Powered Nano- and Microswimmers: From Individual to Collective Behavior,” ACS Nanosci. Au, vol. 3, no. 6, pp. 424–440, Dec. 2023, doi: 10.1021/acsnanoscienceau.3c00038

work page doi:10.1021/acsnanoscienceau.3c00038 2023
[12]

Artificial Acousto‐Magnetic Soft Microswimmers,

D. Ahmed, C. Dillinger, A. Hong, and B. J. Nelson, “Artificial Acousto‐Magnetic Soft Microswimmers,” Adv. Mater. Technol., vol. 2, no. 7, p. 1700050, Jul. 2017, doi: 10.1002/admt.201700050

work page doi:10.1002/admt.201700050 2017
[13]

Selectively manipulable acoustic-powered microswimmers,

D. Ahmed et al., “Selectively manipulable acoustic-powered microswimmers,” Sci. Rep., vol. 5, no. 1, p. 9744, May 2015, doi: 10.1038/srep09744

work page doi:10.1038/srep09744 2015
[14]

Acoustically powered surface-slipping mobile microrobots,

A. Aghakhani, O. Yasa, P. Wrede, and M. Sitti, “Acoustically powered surface-slipping mobile microrobots,” Proc. Natl. Acad. Sci., vol. 117, no. 7, pp. 3469–3477, Feb. 2020, doi: 10.1073/pnas.1920099117

work page doi:10.1073/pnas.1920099117 2020
[15]

Cavitation microstreaming and stress fields created by microbubbles,

J. Collis et al., “Cavitation microstreaming and stress fields created by microbubbles,” Ultrasonics, vol. 50, no. 2, pp. 273–279, Feb. 2010, doi: 10.1016/j.ultras.2009.10.002

work page doi:10.1016/j.ultras.2009.10.002 2010
[16]

The Sound Field,

T. G. Leighton, “The Sound Field,” in The Acoustic Bubble, Elsevier, 1994, pp. 1–66. doi: 10.1016/B978-0-12-441920-9.50006-7

work page doi:10.1016/b978-0-12-441920-9.50006-7 1994
[17]

Micropropulsion by an acoustic bubble for navigating microfluidic spaces,

J. Feng, J. Yuan, and S. K. Cho, “Micropropulsion by an acoustic bubble for navigating microfluidic spaces,” Lab. Chip, vol. 15, no. 6, pp. 1554–1562, 2015, doi: 10.1039/C4LC01266F

work page doi:10.1039/c4lc01266f 2015
[18]

Multiorifice acoustic microrobot for boundary-free multimodal 3D swimming,

N. Mahkam, M. C. Ugurlu, S. K. Kalva, A. Aghakhani, D. Razansky, and M. Sitti, “Multiorifice acoustic microrobot for boundary-free multimodal 3D swimming,” Proc. Natl. Acad. Sci., vol. 122, no. 4, p. e2417111122, Jan. 2025, doi: 10.1073/pnas.2417111122

work page doi:10.1073/pnas.2417111122 2025
[19]

Propulsion of Bubble-Based Acoustic Microswimmers,

N. Bertin et al., “Propulsion of Bubble-Based Acoustic Microswimmers,” Phys. Rev. Appl., vol. 4, no. 6, p. 064012, Dec. 2015, doi: 10.1103/PhysRevApplied.4.064012

work page doi:10.1103/physrevapplied.4.064012 2015
[20]

Ultrasound-driven programmable artificial muscles,

Z. Shi et al., “Ultrasound-driven programmable artificial muscles,” Nature, vol. 646, no. 8087, pp. 1096–1104, Oct. 2025, doi: 10.1038/s41586-025-09650-3

work page doi:10.1038/s41586-025-09650-3 2025
[21]

Acoustic Bubble: Controlled and Selective Micropropulsion,

D. Ahmed, “Acoustic Bubble: Controlled and Selective Micropropulsion,” The Pennsylvania State University, 2015

2015
[22]

Imaging-guided bioresorbable acoustic hydrogel microrobots,

H. Han et al., “Imaging-guided bioresorbable acoustic hydrogel microrobots,” Sci. Robot., vol. 9, no. 97, p. eadp3593, Dec. 2024, doi: 10.1126/scirobotics.adp3593

work page doi:10.1126/scirobotics.adp3593 2024
[23]

Acoustic microstreaming around an isolated encapsulated microbubble,

X. Liu and J. Wu, “Acoustic microstreaming around an isolated encapsulated microbubble,” J. Acoust. Soc. Am., vol. 125, no. 3, pp. 1319–1330, Mar. 2009, doi: 10.1121/1.3075552

work page doi:10.1121/1.3075552 2009
[24]

Acoustic microstreaming around an encapsulated particle,

A. A. Doinikov and A. Bouakaz, “Acoustic microstreaming around an encapsulated particle,” J. Acoust. Soc. Am., vol. 127, no. 3, pp. 1218–1227, Mar. 2010, doi: 10.1121/1.3290997

work page doi:10.1121/1.3290997 2010
[25]

Robust acoustofluidic micromixer based on an ultrathin PDMS microballoon oscillator,

Y. Yang et al., “Robust acoustofluidic micromixer based on an ultrathin PDMS microballoon oscillator,” Sens. Actuators B Chem., vol. 448, p. 139009, Feb. 2026, doi: 10.1016/j.snb.2025.139009

work page doi:10.1016/j.snb.2025.139009 2026

[1] [1]

Rotational manipulation of single cells and organisms using acoustic waves,

D. Ahmed et al., “Rotational manipulation of single cells and organisms using acoustic waves,” Nat. Commun., vol. 7, no. 1, p. 11085, Mar. 2016, doi: 10.1038/ncomms11085

work page doi:10.1038/ncomms11085 2016

[2] [2]

3D steerable, acoustically powered microswimmers for single-particle manipulation,

L. Ren et al., “3D steerable, acoustically powered microswimmers for single-particle manipulation,” Sci. Adv., vol. 5, no. 10, p. eaax3084, Oct. 2019, doi: 10.1126/sciadv.aax3084

work page doi:10.1126/sciadv.aax3084 2019

[3] [3]

Microporous Magnetic Soft Materials with Programmable Locomotion and On-Demand Liquid Cargo Release,

Y. Zhou, F. Kocabas, and Y. Alapan, “Microporous Magnetic Soft Materials with Programmable Locomotion and On-Demand Liquid Cargo Release,” in 2025 International Conference on Manipulation, Automation and Robotics at Small Scales (MARSS), West Lafayette, IN, USA: IEEE, Jul. 2025, pp. 01–06. doi: 10.1109/MARSS65887.2025.11072793

work page doi:10.1109/marss65887.2025.11072793 2025

[4] [4]

Magnetically steerable bacterial microrobots moving in 3D biological matrices for stimuli-responsive cargo delivery,

M. B. Akolpoglu et al., “Magnetically steerable bacterial microrobots moving in 3D biological matrices for stimuli-responsive cargo delivery,” Sci. Adv., vol. 8, no. 28, p. eabo6163, Jul. 2022, doi: 10.1126/sciadv.abo6163

work page doi:10.1126/sciadv.abo6163 2022

[5] [5]

Microrobotics and Microorganisms: Biohybrid Autonomous Cellular Robots,

Y. Alapan, O. Yasa, B. Yigit, I. C. Yasa, P. Erkoc, and M. Sitti, “Microrobotics and Microorganisms: Biohybrid Autonomous Cellular Robots,” Annu. Rev. Control Robot. Auton. Syst., vol. 2, no. 1, pp. 205–230, May 2019, doi: 10.1146/annurev-control-053018- 023803

work page doi:10.1146/annurev-control-053018- 2019

[6] [6]

Mobile Microrobots for Active Therapeutic Delivery,

P. Erkoc, I. C. Yasa, H. Ceylan, O. Yasa, Y. Alapan, and M. Sitti, “Mobile Microrobots for Active Therapeutic Delivery,” Adv. Ther., vol. 2, no. 1, p. 1800064, Jan. 2019, doi: 10.1002/adtp.201800064

work page doi:10.1002/adtp.201800064 2019

[7] [7]

Shape- encoded dynamic assembly of mobile micromachines,

Y. Alapan, B. Yigit, O. Beker, A. F. Demirörs, and M. Sitti, “Shape- encoded dynamic assembly of mobile micromachines,” Nat. Mater., vol. 18, no. 11, pp. 1244–1251, Nov. 2019, doi: 10.1038/s41563- 019-0407-3

work page doi:10.1038/s41563- 2019

[8] [8]

Zhang, N

F. Kocabas, O. Oguztuzun, Y. Zhou, and Y. Alapan, “Magnetic Programming of Soft Materials Using Digitally Processed Laser Heating,” in 2025 IEEE International Conference on Robotics and Automation (ICRA), Atlanta, GA, USA: IEEE, May 2025, pp. 15350–15355. doi: 10.1109/ICRA55743.2025.11127804

work page doi:10.1109/icra55743.2025.11127804 2025

[9] [9]

Multifunctional biohybrid magnetite microrobots for imaging-guided therapy,

X. Yan et al., “Multifunctional biohybrid magnetite microrobots for imaging-guided therapy,” Sci. Robot., vol. 2, no. 12, p. eaaq1155, Nov. 2017, doi: 10.1126/scirobotics.aaq1155

work page doi:10.1126/scirobotics.aaq1155 2017

[10] [10]

Actuation of Mobile Microbots: A Review,

H. Hussein et al., “Actuation of Mobile Microbots: A Review,” Adv. Intell. Syst., vol. 5, no. 9, p. 2300168, Sep. 2023, doi: 10.1002/aisy.202300168

work page doi:10.1002/aisy.202300168 2023

[11] [11]

Acoustically Powered Nano- and Microswimmers: From Individual to Collective Behavior,

J. M. McNeill and T. E. Mallouk, “Acoustically Powered Nano- and Microswimmers: From Individual to Collective Behavior,” ACS Nanosci. Au, vol. 3, no. 6, pp. 424–440, Dec. 2023, doi: 10.1021/acsnanoscienceau.3c00038

work page doi:10.1021/acsnanoscienceau.3c00038 2023

[12] [12]

Artificial Acousto‐Magnetic Soft Microswimmers,

D. Ahmed, C. Dillinger, A. Hong, and B. J. Nelson, “Artificial Acousto‐Magnetic Soft Microswimmers,” Adv. Mater. Technol., vol. 2, no. 7, p. 1700050, Jul. 2017, doi: 10.1002/admt.201700050

work page doi:10.1002/admt.201700050 2017

[13] [13]

Selectively manipulable acoustic-powered microswimmers,

D. Ahmed et al., “Selectively manipulable acoustic-powered microswimmers,” Sci. Rep., vol. 5, no. 1, p. 9744, May 2015, doi: 10.1038/srep09744

work page doi:10.1038/srep09744 2015

[14] [14]

Acoustically powered surface-slipping mobile microrobots,

A. Aghakhani, O. Yasa, P. Wrede, and M. Sitti, “Acoustically powered surface-slipping mobile microrobots,” Proc. Natl. Acad. Sci., vol. 117, no. 7, pp. 3469–3477, Feb. 2020, doi: 10.1073/pnas.1920099117

work page doi:10.1073/pnas.1920099117 2020

[15] [15]

Cavitation microstreaming and stress fields created by microbubbles,

J. Collis et al., “Cavitation microstreaming and stress fields created by microbubbles,” Ultrasonics, vol. 50, no. 2, pp. 273–279, Feb. 2010, doi: 10.1016/j.ultras.2009.10.002

work page doi:10.1016/j.ultras.2009.10.002 2010

[16] [16]

The Sound Field,

T. G. Leighton, “The Sound Field,” in The Acoustic Bubble, Elsevier, 1994, pp. 1–66. doi: 10.1016/B978-0-12-441920-9.50006-7

work page doi:10.1016/b978-0-12-441920-9.50006-7 1994

[17] [17]

Micropropulsion by an acoustic bubble for navigating microfluidic spaces,

J. Feng, J. Yuan, and S. K. Cho, “Micropropulsion by an acoustic bubble for navigating microfluidic spaces,” Lab. Chip, vol. 15, no. 6, pp. 1554–1562, 2015, doi: 10.1039/C4LC01266F

work page doi:10.1039/c4lc01266f 2015

[18] [18]

Multiorifice acoustic microrobot for boundary-free multimodal 3D swimming,

N. Mahkam, M. C. Ugurlu, S. K. Kalva, A. Aghakhani, D. Razansky, and M. Sitti, “Multiorifice acoustic microrobot for boundary-free multimodal 3D swimming,” Proc. Natl. Acad. Sci., vol. 122, no. 4, p. e2417111122, Jan. 2025, doi: 10.1073/pnas.2417111122

work page doi:10.1073/pnas.2417111122 2025

[19] [19]

Propulsion of Bubble-Based Acoustic Microswimmers,

N. Bertin et al., “Propulsion of Bubble-Based Acoustic Microswimmers,” Phys. Rev. Appl., vol. 4, no. 6, p. 064012, Dec. 2015, doi: 10.1103/PhysRevApplied.4.064012

work page doi:10.1103/physrevapplied.4.064012 2015

[20] [20]

Ultrasound-driven programmable artificial muscles,

Z. Shi et al., “Ultrasound-driven programmable artificial muscles,” Nature, vol. 646, no. 8087, pp. 1096–1104, Oct. 2025, doi: 10.1038/s41586-025-09650-3

work page doi:10.1038/s41586-025-09650-3 2025

[21] [21]

Acoustic Bubble: Controlled and Selective Micropropulsion,

D. Ahmed, “Acoustic Bubble: Controlled and Selective Micropropulsion,” The Pennsylvania State University, 2015

2015

[22] [22]

Imaging-guided bioresorbable acoustic hydrogel microrobots,

H. Han et al., “Imaging-guided bioresorbable acoustic hydrogel microrobots,” Sci. Robot., vol. 9, no. 97, p. eadp3593, Dec. 2024, doi: 10.1126/scirobotics.adp3593

work page doi:10.1126/scirobotics.adp3593 2024

[23] [23]

Acoustic microstreaming around an isolated encapsulated microbubble,

X. Liu and J. Wu, “Acoustic microstreaming around an isolated encapsulated microbubble,” J. Acoust. Soc. Am., vol. 125, no. 3, pp. 1319–1330, Mar. 2009, doi: 10.1121/1.3075552

work page doi:10.1121/1.3075552 2009

[24] [24]

Acoustic microstreaming around an encapsulated particle,

A. A. Doinikov and A. Bouakaz, “Acoustic microstreaming around an encapsulated particle,” J. Acoust. Soc. Am., vol. 127, no. 3, pp. 1218–1227, Mar. 2010, doi: 10.1121/1.3290997

work page doi:10.1121/1.3290997 2010

[25] [25]

Robust acoustofluidic micromixer based on an ultrathin PDMS microballoon oscillator,

Y. Yang et al., “Robust acoustofluidic micromixer based on an ultrathin PDMS microballoon oscillator,” Sens. Actuators B Chem., vol. 448, p. 139009, Feb. 2026, doi: 10.1016/j.snb.2025.139009

work page doi:10.1016/j.snb.2025.139009 2026