Bioinspired multi-dimensional anti-counterfeiting device by combining electrochromism and structural color

Multi-dimensional anti-counterfeiting technologies possess multiple color/pattern variations under different conditions, opening up new avenues in information security. Herein, inspired by the blue-ringed octopus, novel multi-dimensional anti-counterfeiting devices are reported by combining electrochromism and structural color with different coloration mechanisms, that is, by introducing colloidal photonic crystals (PCs) in electrolyte of the electrochromic devices (ECDs). Through actively manipulating voltage or passively changing environment background, the degree of light reflectance and transmittance of PCs can be finely modulated, thus realizing the display and hiding of structural colors of devices. Besides, they also feature distinct color evolution under different viewing angles, enabling more optical information to be carried. Laser-etched patterned devices have also been successfully achieved, showcasing superior triple anti-counterfeiting abilities in terms of optical information. Notably, such inherent patterns can further be innovatively switched to different preset background patterns through the synergy of voltage stimulation and background colors. Based on this, a high-level anti-counterfeiting system has been demonstrated, providing the ability to deliver multiple distinct optical information on-demand. It   is believed that such strategy of combining electrochromic and structural color will pave a new platform for designing advanced multi-dimensional anti-counterfeiting devices.