Flexible Self-Powered Multimodal Sensor for Simultaneous Temperature, Strain, and Pressure Detection with Signal Decoupling.

Signal cross-coupling in advanced electronic skin (E-skin) has severely limited its precision in simultaneous temperature, strain, and pressure sensing. Here, we report a flexible, self-powered multimodal sensor based on a heterostructure of redox ion-doped thermoelectric hydrogel and BaTiO3 (BTO) nanoparticle-modified polydimethylsiloxane (PDMS) films. This design achieves independent signal perception with exceptional cross-interference suppression (<4%). Systematic characterization reveals: Thermoelectric response: Seebeck coefficient of 1.05 mV·K-1 (R2 = 0.999) and negligible temperature-induced current deviation (3.32%). Mechanical sensing: Strain sensitivity of 0.91%-1 and pressure sensitivity of 9.76 mV·kPa-1 with an ultrafast response time (22 ms). Robustness: Performance decay of only 3.03% after 150 cyclic tests. Integrated into a finger-joint array, the sensor enables dynamic object surface temperature monitoring, piezoelectric information transmission, real-time sign-language gesture recognition, and intelligent discrimination of interpersonal interaction states. These advancements pave the way for high-precision human-machine interfaces, intelligent wearables, and health-monitoring applications.