Screen‐Printed Multifunctional Anti‐Counterfeiting MXene‐Based Device with Ultra‐Fast On‐Demand Degradability

Abstract Counterfeiting remains a persistent global challenge, and current anti‐counterfeiting technologies are often constrained by single‐stimulus responsiveness and poor environmental compatibility at the end‐of‐life of devices. Herein, a printable, ultra‐fast, degradable, and multi‐stimulus anti‐counterfeiting (MSAC) device based on spectrally selective MXene‐TEMPO‐oxidized cellulose nanofiber (TOCNF) inks is developed, enabling high‐resolution patterning and reversible information encryption/decryption through screen‐printing techniques. TOCNF establishes robust interfacial interactions with MXene nanosheets, forming a hydrogen‐bonded network that significantly enhances the viscoelasticity and nanomechanical properties of the anti‐counterfeiting layer. The resulting MSAC device demonstrates excellent infrared stealth performance in the mid‐infrared range, making it suitable for high‐security identity verification. Furthermore, it offers reversible information encryption, triggered by light or electrical stimuli in the UV–vis‐NIR range via efficient photothermal and electrothermal conversion, enabling dynamic and multi‐modal authentication. Notably, the device exhibits eco‐friendly decomposition into non‐toxic products by ultrasonic sonochemical treatment in hydrogen peroxide (H 2 O 2 ) with only 200 s, representing the record high degradation rate reported among MXene‐based functional materials. This work paves the way for developing multi‐stimulus functional materials for the printable, sustainable, and biocompatible anti‐counterfeiting applications.