Tunable multistability and vibration isolation of programmable metamaterials via modular regulation

Mechanical metamaterials with tunable multistability and vibration isolation are highly desirable for impact protection and vibration suppression in complex service environments. However, in most existing systems, geometric parameters are fixed during fabrication, resulting in predetermined mechanical responses that cannot be reconfigured without remanufacturing. This study propose a modular metamaterial design enabled by thermally programmed shape memory polymers. Thermal-triggered geometric programming reconstructs unit cell end constraints, allowing programmable regulation of stability type and nonlinear force – displacement behavior while preserving structural topology. A programmable stability window is established through parametric analysis, enabling controllable stability transition and load-level tuning. At the metamaterial level, interlayer differentiated programming achieves layered steady-state configurations and designed collapse propagation paths, producing hierarchical peak-sequence responses. Vibration experiments further verify that the isolation onset frequency can be tuned to match different applied masses, with programming shifting the isolation region toward lower frequencies. This work extends thermal shape memory programming from a material response to a structural regulation strategy, providing a post-fabrication route for reconfigurable mechanical performance in multistable metamaterials.