Liquid-Crystal-Powered Metasurfaces for Electrically and Thermally Switchable Photorealistic Nanoprinting and Optical Security Platform

Abstract

Active or reconfigurable metasurfaces have been considered a promising paradigm for dynamic structural coloration and are starting to find their way into the ultra-compact integrated optical display and color printing platforms. Generally, an ideal dynamic structural color platform requires full hue-saturation-brightness (HSB) control, high switching contrast, and a simple operation manner. Unfortunately, to date, it remains challenging to simultaneously achieve all these features using previous approaches. Here, a novel electrically and thermally switchable reflective nanoprinting platform is reported by integrating polarization-sensitive silver nanogroove arrays with a twisted nematic LC cell. Compared to conventional LC-assisted dynamic nanoprinting, the device can simultaneously achieve superior color purity, wider gamut, and higher switching contrast. Moreover, through the implementation of a sub-pixels scheme, arbitrary colors in the color gamut can be created by a mixture of red, green, and blue (RGB) channels at different ratios. As a proof of concept, dynamic switching of photorealistic nanoprinting with full HSB control at a high pixel density (>4,000 pixels per inch) as well as information switching and steganography are demonstrated, suggesting that the device possesses great potential in optical display and information security applications.