This page aims to explore the world records for ultrasonic levitation. These are not yet official records, but it is hoped that in time they will become official. The first consideration is the record definitions. Such definitions did not previously exist and so this page is a first attempt at this task. As you will see I have indentifed holders of some of the records, but not all of them, so this is work in progress. If you have any information on any of these records or ideas for other records, please get in touch.
High-level definitions
The device must use ultrasonic waves, meaning that its operating frequency must be above 20kHz.
To count as levitation, the levitated object must be clear of any other objects. It is suggested that the levitated object should be at least 2cm from other objects.
The levitation should take place on earth and in air at normal room temperatures and pressures.
The record should be in the relevant SI units.
Record 1a – Largest size of levitated spherical object
Size as measured by the diameter of the spherical object, measured in millimetres or metres. The object should remain levitated in a single location for at least 10 seconds.
Date: 23/1/2019
Size: 30mm
Equivalent to 3.5wavelengths at 40kHz
Holders: Seki Inoue, Shinichi Mogami, Tomohiro Ichiyama, Akihito Noda, Yasutoshi Makino, and Hiroyuki Shinoda
Evidence: The Journal of the Acoustical Society of America, 145(1), 328–337. https://doi.org/10.1121/1.5087130
Record 1b – Largest size of levitated object of any shape
Size as measured by the physical dimensions of the object, measured in millimetres or metres. Particular attention is paid to the largest physical dimension. The object should remain levitated in a single location for at least 10 seconds.
Date: 23/1/2019
Shape: Regular octahedron
Size: 50mm
Equivalent to 5.9wavelengths at 40kHz
Holders: Seki Inoue, Shinichi Mogami, Tomohiro Ichiyama, Akihito Noda, Yasutoshi Makino, and Hiroyuki Shinoda
Evidence: The Journal of the Acoustical Society of America, 145(1), 328–337. https://doi.org/10.1121/1.5087130
Record 2 – Heaviest weight of levitated object
Weight defined as the mass of the levitated object, measured in grams or kilograms. The object should remain levitated in a single location for at least 10 seconds.
Date: 20/9/2002
Mass: 2.84g
Object: 4mm diameter Irridium sphere
Holders: W. J. Xie, C. D. Cao, Y. J. Lu, and B. Wei
Evidence: Physical Review Letters, 89(10), 104304. https://doi.org/10.1103/PhysRevLett.89.104304
Record 3 – Fastest moving levitated object
This record refers to the speed/velocity of the levitated object, measured in metres per second. The motions should be linear. The object should be levitated throughout and be stationary at the start and finish.
Date: 13/11/2019
Speed: 8.75m/s
Holders: Ryuji Hirayama, Diego Martinez Plasencia, Nobuyuki Masuda and Sriram Subramanian
Evidence: Nature, 575(7782), 320–323. https://doi.org/10.1038/s41586-019-1739-5
Record 4 – Fastest rotating levitated object
This means size in terms of the physical dimensions of the object, measured in revolutions per second. The rotation should be about a single axis of rotation. The object should be levitated throughout and be stationary at the start and finish.
Date: 10/8/2022
Rotational speed: 6500rps
Holders: Bowen Zhang, Zhenyu Hong and Bruce Drinkwater
Evidence: Physical Review Applied, 18(2), 024029. https://doi.org/10.1103/PhysRevApplied.18.024029
The following records are unclaimed
Record 5 – Smallest size of levitated object
Size as measured by the physical dimensions of the object, measured in micrometres, millimetres, or metres. If the object is spherical then the size is given by the diameter, and if non-spherical then the size is given by the largest dimension. The object should remain levitated in a single location for at least 10 seconds.
Record 6 – Longest duration of levitated object
Duration as measured by the time over which the object remains levitated, measured in seconds, hours, or days. The object should remain levitated in a single location.
Record 7 – Closest approach of two levitated objects
The two objects should be levitated near each other and the distance between them measured. Approach distance as measured by the physical separation of the objects, measured in micrometres, millimetres, or metres. The objects should remain in two stable locations.
Bruce Drinkwater 