Abstract
Negative radiation forces act opposite to the direction of propagation, or net momentum, of a beam but have previously been challenging to definitively demonstrate. We report an experimental acoustic tractor beam generated by an ultrasonic array operating on macroscopic targets (> 1 cm) to demonstrate the negative radiation forces, and to map out regimes over which they dominate, which we compare to simulations. The result and the geometrically simple configuration show that the effect is due to non-conservative forces, produced by redirection of a momentum flux from the angled sides of a target, and not by conservative forces from a potential energy gradient. Use of a simple acoustic setup provides an easily understood illustration of the negative radiation pressure concept for tractor beams, and demonstrates continuous attraction towards the source, against a net momentum flux in the system.
Original language | English |
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Article number | 174302 |
Number of pages | 5 |
Journal | Physical Review Letters |
Volume | 112 |
Issue number | 17 |
DOIs | |
Publication status | Published - 30 Apr 2014 |
Keywords
- acoustic tweezing
- negative radiation force
- Tractor beam
ASJC Scopus subject areas
- Acoustics and Ultrasonics
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Dive into the research topics of 'Acoustic tractor beam'. Together they form a unique fingerprint.Student theses
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Optical and acoustic beam shaping for imaging and manipulation
Yang, Z. (Author), MacDonald, M. (Supervisor), 2014Student thesis: Doctoral Thesis › Doctor of Philosophy
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Press/Media
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Viewpoint: A Macroscopic Tractor Beam with Acoustic Waves
Demore, C. E. M., MacDonald, M. & Cochran, S.
30/04/14
1 item of Media coverage
Press/Media: Research
Profiles
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MacDonald, Michael
- Physics - Professor (Teaching and Research) of Biomedical Photonics
Person: Academic