Reversible Hydro/Halochromic Electrospun Textiles: Harnessing Chromic Technologies in Wearables for Anti‐Counterfeiting Applications

Wearable technology has seen rapid advancement, yet the integration of responsive materials into wearable devices poses significant challenges, particularly in maintaining fabric integrity and user comfort while ensuring sensitivity and responsiveness to environmental stimuli. In this work, these challenges are addressed by developing an ultra‐stable hydrochromic fabric that exhibits both hydro‐ and halochromic responsiveness. Utilizing a bimolecular fluoran dye system composed of a black leuco dye (ODB‐2) and a weak acid developer (benzyl 4‐hydroxybenzoate, B4H), these materials are embedded into a robust fibrous matrix constructed through an electrospinning process with thermoplastic polyurethane (TPU). This approach ensures the breathability, flexibility, and structural integrity of the fabrics, while the hydrophobic nature of TPU contributes to the stability and reversibility of the hydro/halochromic properties. The strategy allows for immediate, high‐contrast color changes upon exposure to water and acidic/basic vapors. These fabrics are also applied in rewritable data encryption, demonstrating their potential in anti‐counterfeiting. Furthermore, the investigation into the mechanical properties of these fabrics confirms their durability and resilience, making them ideal for wearable technology.