Pd Single‐Atom Engineered Janus BiOCl/MXene Heterostructure for Printed Self‐Decoupled Temperature‐Humidity Dual‐Mode Sensors

The advancement of flexible sensing technologies is of paramount importance in biomedical engineering. However, achieving high-fidelity multi-modal temperature-humidity sensing without inter-channel cross-talk and computational post-processing remains a formidable challenge due to overlapping transduction mechanisms. In this study, an unprecedented electron-ion synergistic functional material, featuring a unique inherent self-decoupling capability, was developed based on the Janus hierarchical heterostructure. Through interfacial chemical engineering of Pd single-atom anchoring and heterogeneous-nucleation-driven vertical growth of BiOCl on hollow MXene, the constructed material architecture successfully establishes fundamentally segregated electronic and ionic stimulus-response pathways. Specifically, humidity fluctuations trigger ultra-fast quasi-2D proton conduction facilitated by localized potential wells and electronic redistribution generated around atomically dispersed Pd sites, while temperature gradients induce entropy-driven carrier diffusion within the conductive MXene network. By suppressing signal cross-talk through rigorous mechanistic orthogonality, the fabricated sensing array exhibits outstanding response characteristics (37.5/50 ms for humidity response/recovery and 25/62.5 ms for high/low-temperature response), alongside superior oxidation resistance and robust functional durability (enduring 5000 cycles of testing). Ultimately, leveraging this multi-modal sensing platform and machine learning algorithm, the integrated closed-loop therapeutic system enables accurate evaluation of wound healing progression as well as on-demand drug release, pioneering a new paradigm for next-generation flexible electronics and adaptive healthcare modalities.