Tunable interface states for bending wave separation in one-dimensional demultiplexer

This study presents a reconfigurable demultiplexer designed to spatially separate bending waves using temperature-dependent topological interface modes. Unlike conventional systems that split input signals into fixed frequency components, our innovative design allows for the adjustment of frequency components in response to temperature changes. The metamaterial features a host metallic structure covered with periodically distributed piezoelectric elements that are connected to negative capacitance circuits. Additionally, it incorporates periodically arranged mass-spring resonators made from shape memory alloy. The negative capacitance modifies the stiffness of each unit cell, while the temperature of the shape memory alloy springs controls the resonant frequency of the mass-spring attachments. After analyzing the topological behavior of the unit cell, we conducted numerical simulations to explore a two-channel, topologically protected demultiplexer. The results demonstrate the system's capability to selectively extract signals at frequencies that can be tuned through temperature adjustments, achieving enhanced energy localization in the topological modes.