Rotational mechanical effects of sound

The exploratory studies on sound-matter interaction are to date one of the most promising directions as fundamentalresearch which can be used practically in rheology, medical imaging and other contactless manipulations. So far onlyacoustic radiation force is used in applications.

The study of rotational mechanical effects of sound actually remains in itsinfancy and expected application potential invites a better understanding of acoustic radiation torques and furtherfundamental experimental investigations.

With the aim at going beyond the state-of-the art, the research project proposes toexplore experimentally new facets of the rotational mechanical effects of sound based on the use of acoustic vortex beams,which are characterized by a helical wavefront bearing on-axis phase singularity.

Indeed, depending on the specific wavematterinteraction, acoustic vortex beams can induce various rotational mechanical effects, such as angular displacements,spinning or orbiting motions.

Our approach will first consist to study acoustic radiation torque effects that do not rely onsound-absorption, which corresponds to a sound-matter interaction regime barely explored experimentally.

Also, we willunveil experimentally the existence of recently predicted a spin contribution to the total angular momentum of acoustic vortexbeams.

For these purposes, we will firstly develop a toolbox allowing versatile acoustic vortex beam shaping in the ultrasonicregime owing to 3D printing technologies.

Then, by using obtained vortex beams and appropriately designed sound-matterinteraction schemes, we will detect and monitor quantitatively the sought-after rotational mechanical effects.

By addressingoriginal and timely scientific challenges on experimental grounds, the project will bring new knowledge in the field of acousticangular momenta and set a new state-of-the-art for acoustic contactless manipulations.