Cholesteric Liquid Crystal Microcapsules Exhibiting Triple Response and Dual-Mode Dynamic Regulation for Information Encryption

Abstract

In the digital age, the explosive growth of information exchange has intensified security threats such as data forgery and breaches. Traditional cryptographic materials, constrained by their single-response mode, limited information capacity, and inadequate anti-counterfeiting levels, fail to meet the demands of high-security applications. Here, we introduce a cholesteric liquid crystal microcapsules (CLCMs) with a triple response capability to temperature, UV light, and blue light, enabling dynamic dual-mode tuning of both structural and fluorescence colors. Featuring a core-shell architecture with a polymethyl methacrylate shell and a spiropyran/boron-dipyrromethene co-doped cholesteric liquid crystal core, these CLCMs exhibit exceptional optical properties. The co-doping enables precise control over photochromic and fluorogenic behaviors, while the shell ensures mechanical stability. Within the temperature range of 8-32 °C, the CLCMs display distinct structural colors spanning red, green, and blue. Under UV light exposure, they achieve a rapid green-to-red fluorescence color shift within 2 seconds, while maintaining stable green fluorescence under blue light illumination with minimal temperature interference. A high-capacity visual encryption strategy maps seven colors to digits, enabling the encoding of all 95 displayable ASCII characters. Each unit supports 514425 theoretical variants, offering unprecedented information density for secure data storage and authentication. This platform holds transformative potential for secure data storage, anti-counterfeiting, and real-time authentication in high-value applications such as financial documents and medical records.