Demolding Simulation of Propagation Phase Metasurfaces via Roll-to-Plate Nanoimprint.

Propagation phase metasurfaces have excellent electromagnetic regulation and polarization-insensitive properties, while roll-to-plate nanoimprint lithography (R2P-NIL) is ideal for their large-scale low-cost fabrication. Existing demolding simulations for R2P-NIL are limited to 2D analysis, ignore elastomeric roller impacts, and cannot handle the discrete pillar/hole structures of such metasurfaces. This study establishes a 3D multiscale simulation model using a finite element method combining a macroscopic elastomeric roller deformation model and a microscopic demolding stress model with motion equation-based parameter transfer. Simulation results show macroscopically that zero elastomeric layer thickness minimizes stress, while stress rises and then stabilizes with increasing thickness; a moderately larger roller radius disperses stress; excessive pressure amplifies stress; a microscopically higher resist elastic modulus lowers stress; cylindrical structures have less stress than cuboids; and the limit aspect ratio peaks at a 100 nm line width. This work provides theoretical support for R2P-NIL parameter optimization and promotes the stable large-scale production of propagation phase metasurfaces.