Shoya Yoneda – yoneda-shoya@ed.tmu.ac.jp

Department of Electrical Engineering and Computer Science
Tokyo Metropolitan University
Hino-shi, Tokyo, 191-0065
Japan

Kan Okubo – kanne@tmu.ac.jp

Popular version of 4pPA6 – Miniaturized Acoustic Suction Tweezers: Lift Control and Cap Design for Mobile Applications
Presented at the 189th ASA Meeting
Read the abstract at https://eppro02.ativ.me/appinfo.php?page=IntHtml&project=ASAASJ25&id=3983403&server=eppro02.ativ.me

–The research described in this Acoustics Lay Language Paper may not have yet been peer reviewed–

Can you believe that ultrasound-induced forces can actually pull objects?
It may sound surprising, but this phenomenon is real. In this paper we introduce a fascinating world of sound-based manipulation.

Our research group has long been developing acoustic tweezers capable of picking up tiny objects using ultrasonic forces. (See https://youtu.be/PoZsKjst82g)

In our latest work, we take this idea a step further. By using a remarkably simple structure and cleverly harnessing the lifting force generated by sound, we have created a new acoustic gadget: the acoustic suction tweezer.

Yes —acoustic suction tweezers, sometimes called an “acoustic pipette,” pull objects toward them using sound energy, with no vacuum effect involved.

Proposal Device: Acoustic Suction Tweezer

Sound exerts a force on objects known as the acoustic radiation force, which typically pushes objects away. However, by placing a small aperture unit in front of the transducer, we can shape a unique sound field that transforms this force into attraction and lift —almost like a miniature vacuum cleaner made of sound. To harness this effect, we developed an acoustic focusing cap through extensive trial and error, testing various designs manufactured with a 3D printer to evaluate their performance.

Figure 1. Make various Acoustic Focusing Caps

The figure below shows the simulated sound pressure levels. Relatively high-pressure regions are concentrated near the tip of the cap, which correlates with the generation of attractive acoustic radiation forces in this area.

Figure 2. An Example of Sound Pressure Levels Inside the Cap

How does it compare to other devices?
Our previously proposed acoustic tweezers require large transducer arrays and complex phase control (See https://www.eurekalert.org/news-releases/923462). In contrast, the acoustic suction tweezers overcome these limitations through careful design considerations. Remarkably, they lift objects even larger than the wavelength of sound, such as 15 mm polystyrene spheres.

Practicality
The Acoustic Suction Tweezer excels in practicality; it can be implemented quickly, at low cost, using just a 3D printer and a single ultrasonic transducer.

We confirmed that the device can handle lightweight industrial items such as coated wires and even delicate objects like feathers —materials conventional vacuum tweezers struggle to grasp.

We confirmed that the device can handle lightweight industrial items such as coated wires and even delicate objects like feathers —materials conventional vacuum tweezers struggle to grasp.We expect this device to have strong potential for applications in diverse fields, including medicine, biochemistry, and engineering. We also hope that this system will inspire further innovation and the creation of many other useful acoustic-based tools.