Self-locking non-volatile coding metasurfaces via origami-based mechanical bits

Abstract

Digital coding metasurfaces have revolutionized electromagnetic (EM) manipulation, yet typical tunable approaches based on active components suffer from “volatility”. While mechanical modulation provides a potential solution, current implementations generally lack inherent state-locking capabilities, rendering them vulnerable to environmental disturbances and actuation errors. Inspired by the concept of mechanical bits (MBs), this paper presents a self-locking non-volatile coding metasurface platform enabled by Kresling origami-based MBs. Here, the mechanical bi-stability of individual meta-atoms enables robust binary geometric reconfiguration, with distinct states protected by intrinsic energy barriers. Building upon this concept, equivalent current models accounting for the compression-torsion coupling motion are established and analyzed to design efficient and broadband 1-bit EM units. By integrating tailored metallic patterns onto a multi-material 3D-printed truss-variant array, both transmission- and reflection-type prototypes are proposed and experimentally demonstrated, exhibiting reliable wavefront manipulation capabilities through near-field holographic imaging and far-field beam steering. These results bridge mechanical logic and EM information processing, establishing a universal physical paradigm for constructing low-power, highly robust coding metasurfaces resilient to complex environments. Maintaining states without continuous power remains challenging for tunable metasurfaces. The authors present self-locking non-volatile coding metasurfaces based on origami mechanical bits, enabling holographic imaging and beam steering.