Flexible Dual-Mode Mechanoluminescent–Triboelectric Sensing Based on a PDMS/ZnS:Cu/SDS@PZT Composite

Flexible dual-mode sensors that provide synchronized optical and electrical outputs offer a promising platform for self-powered sensing and human–machine interaction. Here, we developed a composite of polydimethylsiloxane (PDMS), copper-doped zinc sulfide (ZnS:Cu), lead zirconate titanate (PZT), and sodium dodecyl sulfate (SDS) that integrates mechanoluminescent feedback and triboelectric signal generation within a flexible active layer. SDS modification promoted a more uniform dispersion of PZT particles in the PDMS matrix, contributing to improved electrical output relative to the corresponding unmodified-PZT composites. Among the tested formulations, the PZSP-3 device achieved a maximum open-circuit voltage of 90.9 V and a transferred charge of 38.0 nC at a 4 mm contact–separation distance. During a 3000 s test at 5 Hz, the current increased initially and showed no sustained decrease under the specified conditions. In a separate single-electrode configuration, handwritten trajectories produced visible mechanoluminescent feedback together with distinguishable pattern-dependent electrical signals. The capacitor tests showed energy storage on the microjoule scale. These results demonstrate an interfacial-engineering strategy for combining mechanical flexibility, enhanced triboelectric performance, and intuitive optical–electrical visualization, and suggest potential for self-powered human–machine interfaces under the tested conditions.