Dynamically mechanochromic, fluorescence-responsive, and underwater sensing cellulose nanocrystal-based conductive elastomers

Utilizing cellulose nanocrystals (CNCs) to mimic biological skin capable of converting external stimuli into optical and electrical signals represents a significant advancement in the development of advanced photonic materials. However, traditional CNC photonic materials typically exhibit static and singular optical properties, with their structural color and mechanical performance being susceptible to water molecules, thereby limiting their practical applications. In this study, CNC-based conductive elastomers with dynamic mechanochromism, fluorescence responsiveness, and enhanced water resistance were developed by incorporating carbon quantum dots (C QDs) and hydrophobic deep eutectic solvents (HDES) into CNC photonic films via an in-situ swelling-photopolymerization method. Additionally, the abundant non-covalent and hydrophobic interactions within poly(HDES) endow the resulting poly(HDES)/C-CNC elastomer with excellent structural stability, ionic conductivity, and self-adhesive properties, allowing for encrypted information transmission in both air and aquatic environments. The design and application of poly(HDES)/C-CNC elastomers hold tremendous potential for various applications, including anti-counterfeiting labels, human-machine interactions, and wearable devices.