Moving objects with sound

How far are we from moving objects with sound in factories, labs and displays?

Arrays of ultrasonic emitters can hold and move small particles, droplets and thin films in air without touching them. Laboratory work since 2014 has moved millimetre beads, held several particles at once, and levitated a 0.608 g shell 98 mm across in 2025. Those results come from research rigs with small working volumes. The sources reviewed show no production use in manufacturing or pharmaceuticals, and no levitation product from Ultraleap, which is based in Bristol and sells mid-air haptics, or from Pixie Dust Technologies with published payload or throughput figures.

AI illustration · Illustrative scene, not a photograph of the specific device or experiment.
WHERE WE AREEngineering prototypes

Getting closer. Prototypes exist, but not in real-world use.

Working phased-array rigs have been built and tested in several university laboratories, which goes beyond showing the physical principle. None of the sources reviewed describes a system used in a production line, a pilot process, or a pharmaceutical manufacturing step. Reported results cover small objects, short movements and defined workspaces, so the stage is engineering prototype rather than pilot.

The tech tree

Everything recorded on Vrulum that this future needs, oldest foundations at the top and the goal at the bottom. Lines show what each step requires.

What it takes: Moving objects with sound Unlocked Being researched Locked
  1. 2014Acoustic levitationLab demonstration Being researched.
  1. 2011Drug solutions treated without a container in the labDone Unlocked.
  2. 2014Millimetre particles moved in three dimensionsDone Unlocked.
  3. 2018Several particles held at onceDone Unlocked.
  4. 2019Protein crystals measured from levitated dropletsDone Unlocked.
  5. 2025Thin films larger than the acoustic wavelength levitatedDone Unlocked.
  6. 2025Heavier objects levitated in airDone Unlocked.
  7. Date not recordedContainer-free pharmaceutical drying or crystallisation at production scaleNot started Locked.
  8. Date not recordedContact-free handling of components on a production lineNot started Locked.
  9. Date not recordedMid-air displays of graphics from levitated particlesNot started Locked.
  10. Date not recordedCommercial phased-array levitation or tweezers productNot started Locked.
  1. GoalMoving objects with soundGoalRequires: Acoustic levitation, Millimetre particles moved in three dimensions, Several particles held at once, Heavier objects levitated in air, Thin films larger than the acoustic wavelength levitated, Drug solutions treated without a container in the lab, Protein crystals measured from levitated droplets, Container-free pharmaceutical drying or crystallisation at production scale, Contact-free handling of components on a production line, Mid-air displays of graphics from levitated particles, Commercial phased-array levitation or tweezers product. Locked.

The road so far

6 of 10 steps done.

  1. Done · 2014Millimetre particles moved in three dimensions

    Ochiai, Hoshi and Rekimoto used four ultrasonic phased-array modules at 40 kHz to move expanded-polystyrene spheres of 0.6, 1 and 2 mm diameter in a workspace about 520 mm across. Larger spheres were less stable at higher accelerations, and particles fell when they left the stable region. [1]

  2. Done · 17 Dec 2018Several particles held at once

    Marzo and Drinkwater report a 40 kHz system built from two 256-emitter phased arrays that can manipulate up to 25 millimetric particles at the same time. This is stated in the abstract. The full text was not reviewed. [2]

  3. Done · 31 Jul 2025Heavier objects levitated in air

    Hirai and colleagues levitated a hemispherical shell 98 mm across with a mass of 0.608 g, using a 1,494-transducer array at 40 kHz. The measured horizontal range was about 210 × 280 mm at roughly 400 mm height. The maximum controlled horizontal speed was about 9.8 cm/s. The paper states that the restoring force for rotation is not discussed. [3]

  4. Done · 5 Feb 2025Thin films larger than the acoustic wavelength levitated

    Arakawa and colleagues levitated polyimide films about 5 µm thick, with sides of 40 to 50 mm, between two 249-transducer arrays at 40 kHz. The maximum levitated surface density was 3.5 × 10⁻² mg/mm², for a 25 µm polyester film. Films were not rigid and vibrated at the drive frequency. Tilted films and a 45 mm film near the array centre were unstable. [4]

  5. Done · 8 Aug 2011Drug solutions treated without a container in the lab

    Benmore and Weber levitated saturated drug solutions and molecular liquids. Viscous gels formed in 10 to 20 minutes at room temperature, and laser heating vitrified some liquids. They are laboratory results, not a process. [5]

  6. Done · 27 Aug 2019Protein crystals measured from levitated droplets

    Morris and colleagues held droplets coated in silicone oil with no physical support and collected room-temperature X-ray data at Diamond Light Source. A lysozyme dataset reached 1.69 Å from 500 images, and micro-crystal slurries reached about 2.6 Å. The authors estimate diffraction-weighted doses of about 150 to 210 kGy. [6]

  7. Not startedContainer-free pharmaceutical drying or crystallisation at production scale

    The 2011 Popular Summary says the methods may provide practical routes to scaled-up production of amorphous drugs. The abstract does not make this claim, and the sources reviewed report no production process of this kind, or any throughput or yield figures. [5]

  8. Not startedContact-free handling of components on a production line

    A 2025 review from University College London says most hybrid acoustic printing systems still depend on extrusion, photopolymerisation or nozzles, and that scaling acoustic patterning into true 3D fabrication remains a major challenge. No production line using levitation for handling was found in the sources reviewed. [7]

  9. Not startedMid-air displays of graphics from levitated particles

    Ochiai and colleagues mention floating screens as one possible application in a single line, and Pixie Dust Technologies lists a flat particle screen as a case. No display with a published size, particle count, update rate or everyday use was found in the sources reviewed. [1][9]

  10. Not startedCommercial phased-array levitation or tweezers product

    Ultraleap is based in Bristol and describes its products as mid-air haptics and hand tracking. No Ultraleap levitation or tweezers product was found in the sources reviewed. Pixie Dust Technologies describes factory and medicine-handling uses, but its page gives no payload, size or throughput figures. [8][9]

Why it matters

Contact-free handling could protect samples and parts that contact would contaminate, damage or disturb, such as delicate components and drug materials. Mid-air arrays could also change how information is shown if objects can be moved and lit in the air. Whether this becomes practical depends on payload, working volume, stability and control, and the studies so far measure these only under narrow conditions.

What stands in the way

  • Payload: the heaviest result reviewed is a 0.608 g shell, and the densest film held was a surface density of 3.5 × 10⁻² mg/mm². No source reviewed shows a heavy object held stably.
  • Working volume: the 2025 shell was held within about 210 × 280 mm horizontally, and the film work notes that larger films need more transducers, because the size limit depends on the array aperture.
  • Stability and posture: larger particles were less stable at higher accelerations, tilted films were unstable, and rotation of the shell was not addressed.
  • Hardware and control: arrays of 249 to 1,494 transducers need phase-control electronics that grow with the array. The sources reviewed give no power, cost or noise figures.
  • Sample range: Morris and colleagues say the 11.5 V drive voltage is unlikely to be optimal for samples with very different densities or surface tensions, such as crystallisation solutions with high concentrations of volatile components or high-molecular-weight polyethylene glycols.
  • Scale-up: none of the reviewed sources reports an industrial throughput, yield or failure rate for handling, drying or crystallising materials.

Signals to watch

  • Peer-reviewed reports of levitated objects above 1 g, with stated stability, rotation control and workspace size.
  • A published throughput or failure-rate figure for contact-free handling in a production or laboratory workflow.
  • Pharmaceutical drying or amorphisation work that reports batch sizes, yields or quality checks.
  • Ultraleap or Pixie Dust publishing payload, size, power or throughput specifications, or naming paying customers for levitation.
  • Guidance on airborne ultrasound exposure for workers near large arrays.

Sources

  1. peer reviewed paper
    Three-Dimensional Mid-Air Acoustic Manipulation by Ultrasonic Phased Arrays
    Yoichi Ochiai, Takayuki Hoshi, Jun Rekimoto. PLOS ONE, 21 May 2014.
  2. peer reviewed paper
    Holographic acoustic tweezers
    Asier Marzo, Bruce W. Drinkwater. Proceedings of the National Academy of Sciences, 17 Dec 2018.
  3. peer reviewed paper
    Acoustic levitation of objects larger than wavelength using a circular orbital single ultrasound focus
    Ryunosuke Hirai, Yasutoshi Makino, Atsushi Matsubayashi et al.. Journal of the Acoustical Society of America, 31 Jul 2025.
  4. peer reviewed paper
    Acoustic levitation of super-wavelength elastic films using ultrasound phased arrays
    Gakuto Arakawa, Shun Suzuki, Takaaki Kamigaki et al.. Applied Physics Letters, 5 Feb 2025.
  5. peer reviewed paper
    Amorphization of Molecular Liquids of Pharmaceutical Drugs by Acoustic Levitation
    C. J. Benmore, J. K. R. Weber. Physical Review X, 8 Aug 2011.
  6. peer reviewed paper
    Non-Contact Universal Sample Presentation for Room Temperature Macromolecular Crystallography Using Acoustic Levitation
    R. H. Morris, E. R. Dye, D. Axford et al.. Scientific Reports, 27 Aug 2019.
  7. review article
    Acoustics in additive manufacturing: A path toward contactless, scalable, and high-precision manufacturing
    Hongyi Chen, James Hardwick, Lei Gao et al.. Applied Physics Reviews, 1 Jul 2025.
  8. company announcement
    Ultraleap
    Ultraleap, 21 Oct 2026.
  9. company announcement
    Pixie Dust Technologies: Pixie Dust
    Pixie Dust Technologies, 21 Oct 2026.

Last reviewed 21 Oct 2026.