SMP-based multi-stable mechanical metamaterials: From bandgap tuning to wave logic gates

The elastic metamaterials have exceptional physical properties and functions unavailable in natural materials, a major challenge is how to realize the dynamic and stable adjustment of working frequency to control elastic waves. In this work, we propose a method of creating geometrically reconfigurable and mechanically tunable multi-stable metamaterials to realize a kind of tunable elastic metamaterial with a stable state during the active regulation without continuous-consuming energy based on 4D printing technology. The underlying mechanical mechanism of dynamic and stable adjustment is investigated through theoretical model, finite element analysis and experiment. The tunable elastic metamaterial can adjust the starting/ending frequencies and broaden the frequency ranges of bandgaps and control the elastic wave propagation. The method of intelligent and active manipulation of elastic wave can be used in vibration-isolated steady-state adjustable equipment and smart wave device. Inspired by electronic technology, we implement a bi-stable logic-gate elastic metamaterial to correctly execute simple wave logic operations.