A Self‐Powered and Rechargeable Multimodal Hydrogel Sensor with Decoupled Oxygen and Temperature Sensing

Abstract

Wearable self‐powered sensors capable of monitoring multiple physiological signals are highly desirable for next‐generation healthcare electronics, yet achieving decoupled multi‐signal sensing within a single compact system remains challenging. Here, we report a self‐powered, rechargeable multimodal soft sensor (SRMS sensor) based on a multilayered zinc‐air battery design for decoupled O2 and temperature monitoring. The SRMS sensor utilizes a potassium polyacrylate/polyacrylamide hydrogel as the polyelectrolyte, and employs a Co3O4/graphene‐coated nickel foam cathode for O2 concentration monitoring, as well as a Zn‐electrodeposited graphite film anode for temperature sensing. It is demonstrated that the sensor can be used for contactless temperature‐sensing, thermal imaging, and information input through sensor‐array integration. During the respiratory gas monitoring, the SRMS sensor shows decoupled negative and positive responses of relative current change upon O2 and temperature stimuli. The SRMS sensor also successfully distinguishes different respiratory states, identifies sleep‐related respiratory disturbance events, and monitors skin‐temperature variations during sleep. This work provides a novel strategy for constructing multimodal self‐powered soft sensors with decoupled sensing capability, which shows promising applications in wearable healthcare monitoring and contactless information interaction.