Scientists Use Adaptive Algorithm to Fine-tune Acoustic Levitation Technology for Contactless Pick-up
Researchers at the Tokyo Metropolitan University have used adaptive algorithm to enhance the capabilities of existing mid-air acoustic tweezers. The newly improved acoustic tweezers can lift small particles without any physical manipulation or contact. The fine tuning with adaptive algorithm has enhanced the stability of the acoustic tweezers.
Acoustic tweezers are derived from the contactless manipulation or lift-ups similar to magnetic levitation technology, but only in this case, sound waves are used. The acoustic tweezers are used to pick small-sized particles through acoustic radiation in space using Langevin transducers which produce ultrasonic sound wave emitters. By using adaptive algorithm, researchers were able to solve the complex problem associated with previous generations of transducer arrays and oscillators used in the acoustic tweezers.
Here’s the video of the demonstration of how acoustic tweezers work:
The researchers majorly focused on building the stability of the acoustic tweezers and transportation of particles. They developed an adaptive algorithm for a multi-channel hemispherical transducer array to control non-contact manipulation. The team was able to create sound waves by controlling the frequency, amplitude, phase, and direction of transducer arrays to push, lift and hold the particles. The outcome of the research shows that if opposing halves of the multi-channel hemispherical transducer arrays are operated in “in and out” phase using adaptive algorithm, the acoustic tweezers showed better stability within the wave-field while moving particles in contactless pickups. During the “in phase” of oscillation, the tweezers are able to lift and move the particles within the area of influence, while during the “out phase” the tweezers are able to control the lift and reposition the particles to the center for a more controlled pickup using levitation technology.
This study is published in the Japanese Journal of Applied Physics, and published on behalf of The Japan Society of Applied Physics by IOP Publishing Ltd. This research was partially funded by The Murata Science Foundation.
Possible applications of acoustic levitation technology
Contactless acoustic levitation tweezers developed by various researchers are used in a variety of processes. Most of them are used at places of high-risk bio hazard, radioactivity, or at places where chemical inertness is required. We can expect advanced level of use in bio-manufacturing, regenerative drug development and re-engineering, neuroscience, 3D cell forcing / cell extraction, semiconductor development, and so on.
Shota Kondo and Kan Okubo; 2022 Jpn. J. Appl. Phys. 61 SG8004