Electro-mechanical multi-branch channel driven by higher-order topological rainbow

作者：Jiahao Li, Hongying Tang, Yuxin Chen · 发表于：Mechanics of Advanced Materials and Structures · 年份：2025 · DOI：10.1080/15376494.2025.2468378 · 被引用次数：2 · 研究领域：Nonlocal and gradient elasticity in micro/nano structures、Topological Materials and Phenomena、Nonlinear Photonic Systems

In this paper, we propose an elastic tunable phononic plate based on a negative capacitance circuit. It is found that the Bragg bulk bandgap can be broadly tuned by judiciously adjusting the sliding rheostat, thereby overcoming the inherent frequency limitations of conventional elastic topological insulators (ETIs). Moreover, the piezoelectric phononic plate proposed in this study originates from the classical Su-Schrieffer-Heeger (SSH) model, whose second-order topology is intrinsically linked to the Zak phase. Thus, fine-tuning the resistance of the sliding rheostat effectively enables the adiabatic shifting of the edge and corner states across the frequency spectrum. By assembling piezoelectric phononic plates with varying gradient coefficients, we design and numerically demonstrate elastic wave splitters specifically targeting edge and corner states. Inspired by the rainbow effect and the multiple-channel wave transport, we designed a multi-branch structure where elastic waves are directed into different channels at varying frequencies. The proposed multi-branch structure can effectively identify the frequency and complete the guiding function. This work offers valuable insights for practical energy harvesting applications from elastic waves.