Ag@BaTiO3 Core–Shell Structured Fillers Enabled P(VDF-TrFE) Composite Films for Self-Powered Pressure and Temperature Dual Mode Sensing

Abstract

Flexible dual-mode pressure–temperature sensors face three key bottlenecks: low electrical conductivity, poor thermal conduction, and severe signal crosstalk. To overcome these challenges, we design Ag@BaTiO3 core–shell fillers embedded in a P(VDF-TrFE) matrix. The BaTiO3 core provides a stable dielectric response for temperature sensing, while the conductive Ag shell simultaneously enhances interfacial polarization, promotes β-phase nucleation, and improves thermal transport across the composite. The optimal formulation (15 wt % filler with 10 wt % Ag loading) yields a high β-phase content of 86.7% and a piezoelectric coefficient of 21.1 pC/N. The assembled piezoelectric nanogenerator delivers an open-circuit voltage of 29.25 V, a short-circuit current of 0.85 μA, and an output power of 25.1 μW, maintaining excellent stability over 4800 operating cycles. Moreover, the same film exhibits a temperature sensitivity of 0.8% °C–1 and a resolution of 0.1 °C. Notably, pressure and temperature are transduced through independent physical channels─piezoelectric and capacitive, respectively. This core–shell strategy thus provides a scalable and efficient route toward self-powered, multifunctional sensors.