High-Performance Multifaceted Piezoelectric Composite Nanogenerators for Weight-Monitoring Sensors

Flexible, multifaceted poly(vinylidene fluoride)/selenium microrod composite films (PS-CFs) were developed by a solution casting (SC) process to convert abundant mechanical energy sources into useful electricity. The PS-CFs (0 and 4 wt %) showed an equal value of electroactive phases (EAPs) and enormous differences in Pr values (10 and 90 nC/cm2, respectively) due to the micropores between the grains that act as charge-trapping carriers and the enhancement of electrical conduction between the −CH2–/–CF2– molecular chains via selenium microrods (Se-MRs). The 4 wt % PS-CF-based piezoelectric generator (PG) delivered an instantaneous power density of ≈0.56 μW/cm2 at 60 MΩ from a 10 N force. The thickness dependence of ferroelectric loops, weight ratio dependence, dielectric properties, leakage current, and energy-harvesting capabilities of the PS-CFs were evaluated systematically. The output power of the PS-CF-PG device, along with the switching circuit powering of five commercial light-emitting diodes, and electronic display devices, suggested that the device could operate as a stand-alone power source. Next, we demonstrated that the as-fabricated PS-CF-PG device could work as a weight-monitoring sensor having a sensitivity of 0.2 V/g. The present work paves the way toward developing cost-effective, highly efficient ferroelectric films for next-generation energy harvesting and smart sensor devices. It also eliminates the use of the typical synthesis method with filler compounds and simplifies the working mechanisms.