Hybrid-doped elastomeric optical fiber sensor enabling decoupled strain-temperature sensing for wearable applications

Thermal and mechanical stimuli are fundamental modalities underpinning human motion monitoring, health assessment, and human-machine interfaces. Despite notable progress in flexible and wearable electronics, the simultaneous and interference-free detection of thermal and mechanical stimuli within a single sensor remains elusive. Herein, we presented the design and fabrication of a hybrid-doped elastomeric optical fiber (HEOF) sensor that enables dual-parameter sensing of strain and temperature with effective cross-talk suppression. The HEOF sensor was constructed based on a PDMS optical fiber spatially doped with gold nanoparticles (GNPs) and lanthanide-based upconversion nanoparticles (Ln-UCNPs), producing a hybrid optical medium that integrates plasmonic and luminescent responses. This hybrid design provides spectrally decoupled readout of strain and temperature with accuracies of 0.3% (strain) and 0.7°C (temperature). We demonstrate the versatility of the sensor through its integration into wearable masks, gloves, and bandages that enable simultaneous monitoring of physiological thermal dynamics and body motions in real time, offering new prospects for next-generation smart wearables.