Self-Powered Sensors Made with Fabric-Based Electrodes and a Conductive Coating

Amidst the growing challenge of meeting global energy demands with conventional sources, self-powered devices offer promising solution. Flexible and stretchable electronics are pivotal in wearable technology, enhancing the scope and functionality of these devices. This study employs potassium sodium niobite-lithium antimonate (K_0.5Na_0.5NbO₃-LiSbO₃) nanoparticles as fillers in polyvinylidene fluoride (PVDF) to fabricate piezoelectric thin films. These films are integrated with fabric-based electrodes to develop high-performance, flexible self-powered sensors. The sensor comprises a fabric-based electrode with polypyrrole (PPy) coated on plain nylon fabric, a 0.93KNN-0.07LS/PVDF composite piezoelectric thin film, and a protective PET layer. Results demonstrate that the 0.93KNN-0.07LS/PVDF-PPy/nylon composite sensors exhibit a stable piezoelectric output. Under 6 Hz and 10 N excitation, the piezoelectric output reaches approximately 6.1 V upon pressing. Additionally, the device shows good linear sensitivity in the 2-20 N pressure range and produces clear, regular output waveforms under cyclic pressures of varying frequencies and amplitudes, indicating excellent response repeatability. Even after extensive bending, twisting, and 5000 pressing cycles, the sensors maintain considerable cyclic stability, demonstrating high durability. These tests collectively indicate that the developed sensors possess high sensitivity, flexibility, durability, stability, and significant self-powered potential. This research provides a reference for the next generation of textile-based electrodes and offers potential strategies for flexible, wearable applications.