Topological acoustic demultiplexer/switch featuring three output channels using phononic crystals

Abstract This paper presents the design and simulation of a topological phononic crystal-based acoustic demultiplexer featuring three distinct output channels. The demultiplexer consists of a square lattice of PMMA scatterers placed within an air matrix, where topological and trivial phase transitions are achieved by adjusting the scatterer angles without altering the lattice geometry. The primary goal of this research is to optimize frequency separation within a topological framework, enhancing the precision and efficiency of acoustic wave transmission. The transmission spectra were computed across the frequency range of 15.2 to 16.2 kHz, corresponding to the edge modes of the input pathway. This frequency range, which defines the propagation band of the input edge mode, served as the basis for structural analysis and the selection of optimal operational frequencies. Through numerical simulations, 15.5, 16.098, and 15.84 kHz were identified as the optimal frequencies, corresponding to output channels 1, 2, and 3, respectively. The results highlight the capability of the proposed design to achieve precise and interference-free frequency separation, demonstrating its superior performance as an acoustic demultiplexer. This study advances the field of topological phononic crystal design and offers significant potential for applications in advanced communication systems and acoustic signal processing. Additionally, switching capability for each frequency was developed, allowing each frequency to pass through all three output paths by adjusting the scatterer angles in specific regions.