Dual‐Mode Thermo‐Responsive Janus Cellulosic Textiles for Visual Sensing, Adaptive Thermal Regulation, and Synergistic Bio‐Protection

ABSTRACT Wearable textiles for smart body‐surface temperature monitoring and thermal management have attracted enormous interest. Nevertheless, it remains challenging to simultaneously achieve high‐sensitivity thermal response, visual temperature feedback, and stable photothermal regulation on textile materials. To address this issue, we propose a Janus bilayer strategy by constructing a conductive thermosensitive MXene/poly(3,4‐ethylenedioxythiophene)–poly(styrenesulfonate) (PEDOT: PSS) layer (MPC) on one side and a reversible thermochromic microcapsule layer (TCMs) on the other side of flexible cellulosic nonwovens (CNWs), achieving dual‐mode synergistic response while overcoming the limitations of single‐mode textiles in signal stability and wearable reliability. The spatially independent but mechanistically complementary layers enhance measurement reliability and intuitive visual feedback. The devices exhibit high sensitivity (0.018°C −1 ), rapid response/recovery, and a broad monitoring range. Leveraging the high thermal conductivity of MXene and microcapsule thermochromism, the bilayer enables synergistic electrical and optical sensing under skin‐contact conditions. Additionally, the smart textile achieves >99.99% antibacterial efficiency through synergistic photothermal/photodynamic therapy and provides switchable body‐surface thermal management, further stabilizing temperature sensing in practical use. This study realizes the unique integration and synergy of multiple functions on cellulose‐based flexible materials, presenting an expandable strategy for the design of health‐monitoring systems and multifunctional wearable textiles.