Subwavelength acoustic energy harvesting via topological interface states in 1D Helmholtz resonator arrays

We have theoretically and experimentally demonstrated subwavelength acoustic energy harvesting via topological interface states in 1D Helmholtz resonator arrays. The system can produce two types of bandgaps the realm due to resonance band folding mechanism, respectively. Through analyses Zak phase eigenfield distributions, properties band-folding-induced gaps be changed by tuning lattice structural parameters, while those resonant maintain stability. When different arrays are spliced together, will appear but do not exist gaps. experimental measurements agree well with theoretical prediction. Our study expands applicability insulators a compacted platform.