Ag Nanocrystalline Decorated Hollow MXene Enabling Dynamic Heterojunction Network: An Interfacial Molecular Engineering for Self‐Decoupling Thermoelectric‐Piezoresistive Dual‐Mode Sensing

ABSTRACT The advancement of flexible sensing technology is pivotal for driving next‐generation innovations in human–machine interactions, biomimetic skins, and intelligent physiological supervision. Whereas, realizing multi‐modal monitoring systems capable of simultaneous sensing to pressure stimuli and thermal stimuli remains a formidable challenge. Herein, a flexible dual‐mode chemical sensing system is developed based on the thermobaric‐field‐modulated dynamic heterojunction network, which is functionalized through molecular‐scale chemical engineering of Ag nanocrystalline decorated activated hollow MXene (22, 26, and 32 ms for the response of pressure and high/low‐temperature stimuli). The self‐decoupling mechanism of the system is established by methodically analyzing pressure‐induced quantum tunneling with interface chemistry evolution and temperature‐driven modulation of electronic structure/potential barrier at heterojunction interfaces, arising from the competitive separation of charge carrier scattering and transporting. Meanwhile, the unique interfacial molecular engineering of the covalently crosslinked PEI/GA activation layer endows the sensing system with exceptional structural stability (below 4% attenuation of the response value after 500 bending cycles) and operational durability (over 5000 cycles of periodic testing). In combination with the machine learning algorithm, the monitoring accuracy and self‐decoupling capability of the integrated dual‐mode sensing device are substantially enhanced, transcending the development boundaries in the progression of intelligent robotics, flexible sensing, and physiological monitoring.