Dual-Mode Anti-Counterfeiting System via Hydrogel-Based Reconfigurable Metasurfaces

Metasurfaces made up of tunable material can reconfigure the optical properties, hereby, contributing new opportunities for functional. It can perform diverse optical responses depending on external stimuli, which can be employed in visually discernable displays and anti-counterfeiting markets. Here, we demonstrated the dual-mode anti-counterfeit metasurfaces via single-step hydrogel nano-imprinting. The hydrogel metasurface has encrypted the information from the near and far-fields separately. The initial state can decode the information 1 the format of holography imaging in a far-field under the RCP rotated laser beam. On the other hand, information 2 is encrypted in near-field that can detect by optical microscopy. When the metasurface was exposed to a high humid condition such as exhaled breath, the hydrogel meta-atom can swell then aggregate with each other. Through the process can be revealed hidden information (2) in the near-field. In terms of mass-production and functionality, the dual-mode anti-counterfeiting metasurface can be expected to be actively applied to the future anti-counterfeiting industry.