Hierarchically structured fiber sensors capable of multimodal, reduced cross-talk detection of strain, pressure, and temperature are highly desirable for smart textiles, yet remain challenging to realize within a single textile-friendly architecture. Here, a wool-decorated multimodal fiber sensor (WDMFS) is reported that integrates piezoresistive (PR), piezocapacitive (PC), and thermoresistive channels along a coaxial fiber comprising a silver-embedded polyurethane core, a liquid metal (LM) shell, and an outer Ag‑embedded fine‑wool sheath that serves as a textile‑like interface. The PR channel provides nearly hysteresis-free strain sensing up to 110% with a gauge factor of 0.77%−1 and demonstrates stable operation over 2500 cycles. The PC channel exhibits a pressure sensitivity of 0.002 kPa−1 over 0–100 kPa with millisecond-scale response and recovery times, and the thermoresistive channel shows a sensitivity of 0.0004 °C−1 with linear response between 10 and 80 °C. Within this hierarchical architecture, the PR channel is responsive to tensile strain, the PC channel is sensitive to normal pressure, and the LM thermoresistive channel tracks temperature variations, this selective channel responsiveness minimizes signal overlap and thereby enables multimodal sensing with reduced cross-talk. Beyond enabling multimodal transduction, the fine‑wool sheath further enhances breathability and sewability by mitigating the tackiness of elastomer encapsulation, enabling integration into fabrics for joint motion monitoring or respiration sensing, thereby establishing the WDMFS as a promising building block for next-generation wearable electronics and smart textiles.
Tsogbayar et al. (Mon,) studied this question.