Flexible Multilayer Metasurfaces: Design and Applications on Foldable and Conformable Substrates

Abstract Metasurfaces offer effective optical modulation and compact solutions for integrated optoelectronic circuits. Multilayer metasurfaces surpass single‐layer counterparts in functionalities, enabling more complex manipulation of phase, amplitude, and polarization. However, existing multilayer metasurfaces lack reconfigurability based on flexible configurations, limiting their applications in dynamic and shape‐constrained scenarios. Here, a multilayer metasurface platform utilizing a foldable and conformable flexible structure is introduced. The foldability enables coupled or decoupled multilayer metasurfaces by reconfigurable folding alignment. To validate this technology, the previously established flexible metasurface fabrication techniques are employed. The coupled multilayer metasurface is demonstrated by an inverse‐designed 1D multilayer zoom metalens that achieves a numerical aperture (NA) from 0.80 to 0.12 by altering the polarization state of incident light from X‐ to Y‐polarization. For the decoupled multilayer metasurface, a refractive‐meta hybrid system is demonstrated, featuring metalens that operates on curved surfaces and can switch between a near‐diffraction‐limited telephoto mode and an 80° wide‐angle mode. The exceptional performance of the two validated devices on this platform highlights its superiority as a comprehensive design platform for multilayer metasurfaces. Notably, its potential for operation on non‐planar forms offers promising applications for miniaturized optoelectronic devices such as augmented reality displays and wearable medical devices.