Acoustic seminar | 10 October 2025

This talk addresses the mechanical action of monochromatic acoustic waves. The field traces back to Umov’s work in 1874 on energy flow in fluids and Dvořák’s first experiments on acoustic radiation pressure in 1877. We present a unifying perspective on acoustic forces and torques acting on particles of various kinds. Our approach relies on the universal connection between the local energy, momentum, and spin densities of wave fields and the corresponding forces and torques exerted on small particles. We further highlight nontrivial cases, such as lateral and pulling forces, as well as effects in bi-anisotropic particles. Finally, we discuss the role of resonances in compact acoustic scatterers and the resulting acoustomechanical phenomena.

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

- Main review paper: arXiv:2410.23670 (2024)
- Force on small acoustic particles: Phys. Rev. Lett. 123.18, 183901 (2019)
- Acoustic lift effect and lateral forces: Phys. Rev. Appl. 22.6, 064041 (2024)
- Sorting of Mie resonant particles: Phys. Rev. Appl. 24.3, 034019 (2025)
- Symmetry approach to eigen modes classification: Phys. Rev. B 105.16, 165311 (2022)