Born approximation of trapping forces by acoustical Bessel and vortex fields

Area of Science:

• Acoustics
• Wave physics
• Scattering theory

Background:

• Acoustic radiation forces are utilized for trapping diverse objects in scientific research and practical applications.
• Existing models for acoustic trapping include partial wave expansion and Gorkov force potential.

Purpose of the Study:

• To extend the Born approximation method for analyzing acoustic trapping forces.
• To investigate trapping forces on spherical and nonspherical objects of arbitrary size using acoustic Bessel and vortex fields.
• To compare the Born approximation results with conventional models.

Main Methods:

• Extension of the Born approximation method to acoustic scattering problems.
• Analysis of two- and three-dimensional acoustic Bessel and vortex fields.
• Comparison with partial wave expansion and Gorkov force potential models.

Main Results:

• The Born approximation accurately predicts trapping forces for weakly scattering objects up to multiple wavelengths.
• The Gorkov force potential, aided by the Born approximation, provides insights into trapping forces on large objects beyond the Rayleigh scattering regime.
• The study reveals the influence of beam parameters, object shape, and orientation on trapping behavior.

Conclusions:

• The extended Born approximation is a valuable tool for studying acoustic radiation forces.
• This research guides the development of simplified acoustic tweezers for arbitrary-shaped particles.