Massively Produced Dual‐Sided Liquid Crystal Metasurfaces for Multi‐Level Anti‐Counterfeiting with Eleven Security Channels

Abstract To enhance the information storage capacity of a single device, the combination of different types of encryption and holographic devices emerges as a continuous area of research. Although metasurfaces exhibit significant variation in meta‐atoms, the display channels of metasurfaces rely on increasing the size and area of meta‐atoms. This undoubtedly introduces complexity in metasurface design and manufacturing. Additionally, planar liquid crystals (LCs) have limited freedom in adjusting the vector angle of LC molecules. In this work, metasurfaces and LCs are combined to demonstrate a multi‐level encryption and display function. The small pixel size of the metasurface, coupled with a large deflection angle, enables the integration of multiple LC patterns in limited space. By gradient descent algorithm, ten holographic images are generated through polarization and distance variations. The device with dual‐layer metasurface and LC structure supports ten far‐field holograms and one near‐field nanoprinting image with just 4 mm thickness. For mass production, a high‐refractive index TiO 2 ‐based resin composited metasurface is fabricated using a high‐throughput nanoprinting along with a Digital Micromirror Device (DMD) technique to produce small pixel size (2.16 µm) LC patterns. The design and fabrication method establish a foundation for high‐throughput multi‐level encryption and display in future metasurface‐LC composite devices.