Microwave seminar | 17 April 2023

Using well-established methods from optics, we examine acoustic radiation force on anisotropic particles. We establish that accounting for self-action of the scattered acoustic field can lead to the appearance of the 'recoil' force effect which physically corresponds to force arising due to asymmetric scattering, and prove that this effect leads to the emergence of lateral forces on anisotropic particles in monopole-dipole approximation. We further extend our analysis to the case of Mie-resonant particles, and discover that asymmetric scattering on anisotropic particles in resonant conditions can lead to dynamically stable configurations with strong lateral forces, which we brand 'acoustic lift' effect by analogy to well-known optical effect.

Main paper/arXiv, related to the seminar, and other references

1. Toftul ID, Bliokh KY, Petrov MI, Nori F. Acoustic Radiation Force and Torque on Small Particles as Measures of the Canonical Momentum and Spin Densities. Physical Review Letters. 123, 183901 (2019).
2. Toftul, I., Bliokh, K., & Petrov, M. Acoustic forces and torques: Directional scattering and acoustic spin. AIP Conf. Proc., 2300(1), 020127 (2020).