Reflective acoustic metasurface design by moving morphable components and genetic algorithms

We design reflective acoustic metasurfaces using moving morphable components and genetic algorithms. The presented method is applied to local and nonlocal design of acoustic devices. In the local design approach, individual unit cells are optimized independently based on the generalized Snell's law (GSL) to manipulate wavefronts through phase gradient along the surface. In contrast, the nonlocal approach optimizes a supercell based on the diffraction theory, allowing consideration of interactions between unit cells. Significant performance improvement of the metasurface is observed, particularly for the larger reflection angle, where the local approach using GSL encounters limitations. This work demonstrates the potential of the presented method in advancing the design of acoustic metasurfaces.