High‐Performance Hydrogel‐Based Temperature Sensor by Integrating Ion Channels and Stabilized Ion Gradients

ABSTRACT Flexible ionic temperature sensors hold great promise for wearable applications but are hindered by sluggish response and insufficient sensitivity. Herein, we develop a high‐performance polyacrylamide (PAM) hydrogel‐based temperature sensor by integrating single‐walled carbon nanotube (SWCNT) ion channels and tailored zinc ion gradients, stabilized by a sodium alginate semipermeable membrane. SWCNTs reduce the activation energy of Zn 2 + migration and provide low‐tortuosity pathways, while the ion gradient lowers migration barriers and enhances directional transport. Their synergy yields a high sensitivity of 10.2%/°C, an ultrafast response/recovery time of 0.9/0.98 s, a detection limit of 0.01°C, and stable performance over 140 cycles. Powered by a flexible zinc‐ion battery (16.2 Wh m − 2 , 84.5% capacity retention at 180° bending), the sensor enables cordless monitoring in cold chain logistics, battery thermal management, and human respiratory sensing. Additionally, it exhibits antibacterial activity against Staphylococcus aureus (≈40% microbial biomass reduction compared to the control) and accelerates wound healing via downregulating IL‐6 and TNF‐α, offering a versatile platform for intelligent monitoring and biomedical engineering.