Flexible Zr-Doped BaTiO₃/PDMS Piezoelectric Nanogenerator for Self-Powered Energy Harvesting and Real-Time Wireless Impact Monitoring Applications

Abstract

Flexible piezoelectric sensors capable of simultaneously harvesting mechanical energy and sensing dynamic pressure are highly desirable for wearable electronics and real-time health and sports monitoring. In this work, a high-performance flexible piezoelectric nanogenerator and pressure sensor based on zirconium-doped barium titanate (BaZrₓTi 1-x O₃, BZT) embedded in a polydimethylsiloxane (PDMS) matrix is developed and systematically investigated. BZT ceramics with varying zirconium doping concentrations were synthesized via a solid-state reaction method, and the optimized 7 mol% Zr-doped composition exhibited enhanced crystallinity, uniform microstructure, and improved piezoelectric characteristics. Flexible composite films were fabricated by incorporating BZT particles into PDMS with different filler loadings, and the electrical output performance was evaluated under periodic mechanical excitation. The device containing 20 wt% BZT demonstrated optimal performance, delivering a peak-to-peak output voltage of approximately 70 V and a current of 0.90 µA, attributed to efficient stress transfer, optimized surface roughness, and balanced mechanical flexibility.Furthermore, the practical applicability of the device was demonstrated through a self-powered, wireless impact-monitoring system for rugby players, integrated with an ESP32 microcontroller and an IoT-based Blynk interface. The system enabled real-time detection and classification of impact severity without the need for an external power source. This study highlights the potential of BZT/PDMS composite devices for flexible self-powered sensing in wearable safety and sports monitoring applications paving towards future Artificial Intelligence of Things (AIoT).