Meta‐Rod Mechanical Metamaterials With Programmable Reconfiguration

ABSTRACT Deformable rod‐shaped structures, such as continuum robot arms and deployable space mechanisms, provide efficient solutions that combine compact space occupation, convenient transportation, and multi‐functional reconfiguration. However, existing rod‐shaped smart structures suffer from a deficient reprogrammable space of shape transformations, limited deformation accuracy, and complex real‐time morphing control, which hinder their miniaturization, precision, and integration. This study introduces a new class of 1D mechanical metamaterials, named Meta‐rods. Activated by a single temporary axial displacement input, Meta‐rods can program and sustain large, complex deformations from rod‐shaped unit cells, including axial translation, bending, twisting, radial expansion, volumetric morphing, and their combinations. Constructed from bistable Nitinol wires, shape transformations can be locked at the mechanical stable stage without continuous maintenance control. The Meta‐rod prototypes a mapping catheter for Atrial Fibrillation treatments, demonstrating self‐sustained deployment under dynamic flow and pressure conditions. The proposed versatile framework for developing reconfigurable building blocks paves the way for advancements in 1D mechanical metamaterials with programmable shape reconfiguration.