Generation of 2D and 3D acoustic lattices in midair using polygonal active diffraction gratings

This paper presents a method to generate two- and three-dimensional periodic or quasi-periodic acoustic lattices in air using polygonal active diffraction gratings. The radiated field depends on design parameters and is well predictable in terms of a superposition of oblique plane waves, with very good agreement with simulations and experiments. Our device represents a simple and efficient approach for producing acoustic lattices with attractive advantages, such as planar single-sided geometry, simple electronics, axial steering, and broadband operation. The design is scalable and compatible with other scientific applications, such as microfluidic platforms.