Mechanically Programmable Electromagnetic Metamaterials for Generalized Phase Tailoring With Zero Static Power Consumption.

Abstract

Mechanically modulated reconfigurable electromagnetic metamaterials represent a promising avenue for flexible wavefront manipulation. However, most mechanically tunable designs rely on collective deformations and continuous external loading, leading to limited programmability and high static power consumption. Here, we present a mechanically programmable electromagnetic metamaterial enabled by 3D-printed shape memory polymer (SMP) compression-torsion coupling structures integrated with the three-fold symmetric three-armed meta-atoms (C3 meta-atoms) for generalized phase tailoring with zero static power consumption. The compression-torsion coupling structures enable deterministic and independent in-plane rotation of each unit cell under vertical compression, while the C3 meta-atoms provide sixfold cross-circularly polarized phase amplification, achieving full 0°-360° phase coverage with a narrow rotational angular range of 0°-60°. Leveraging the intrinsic shape-locking and shape-recovery properties of SMP, arbitrary phase distribution patterns are attainable via mechanical coding without sustained power consumption, and can be repeatedly erased and rewritten via thermal recovery. Numerical simulations and experimental characterizations reveal the design principle and operation mechanism of the metamaterial, verifying its programmable functionalities through demonstrations of anomalous refraction, reconfigurable metalens, and orbital-angular-momentum (OAM) generators. These findings provide a conceptual framework for low-energy, programmable, and reconfigurable wavefront modulation, laying a foundation for advancing next-generation mechanically programmable electromagnetic metamaterials.