Tensegrity X‐Unit Metamaterials With Programmable Wave Dynamics

Architected mechanical materials enable programmable dynamic behavior through geometry and internal constraint rather than material composition alone. The present work introduces a minimal tensegrity‐based architected material platform built from 3D X‐units composed of compressed struts and prestrained elastic ties. Under axial deformation, geometric reconfiguration of the prestrained cable network modifies the tangent stiffness of the unit, producing a nonlinear mechanical response governed by cable prestrain and unit‐level stiffness. An exact closed‐form constitutive description is derived and quantitatively validated through quasi‐static experiments on additively manufactured prototypes, establishing a direct link between architecture, equilibrium state, and effective stiffness. Assemblies of X‐units into 1D wave‐guiding architectures reveal that stiffness contrast, inertia, and operating deformation enable reconfigurable wave‐dispersion characteristics, including the opening, shifting, and suppression of frequency bandgaps. Intrinsic geometric nonlinearity further introduces amplitude‐dependent filtering, allowing the dynamic response to adapt to excitation level without changes in composition or topology. Finite‐structure simulations demonstrate pass‐band transmission, bandgap localization, and strong wave reflection from isolated prestrain or mass defects, confirming that lattice‐level functionality emerges from unit‐scale design. Together, these results establish tensegrity X‐unit architectures as a simple, fabrication‐ready platform for programmable and adaptive mechanical metamaterials in which dynamic function is encoded by geometry and prestress.