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.