Enhanced self-driven flexible piezoelectric nanogenerator sensor based on NaNbO₃/P(VDF-TrFE) films for security applications

The self-driven flexible piezoelectric sensor has wide application prospects in areas such as health monitoring, human-machine interaction, and warning detection due to its advantages of non-toxicity and high sensitivity. In this study, a composite film of poly(vinylidene fluoride-trifluoroethylene) [P(VDF-TrFE)] doped with NaNbO₃ (NN) was prepared by electrospinning. The highly oriented NN particles promote the formation of P(VDF-TrFE) β phase, reaching a maximum β phase content of 91%. Under mechanical motion at a frequency of approximately 3 Hz, the piezoelectric nanogenerator (PENG) fabricated from the nanofiber membrane achieved a maximum piezoelectric output of 17.3 V and 12 V in the transverse and longitudinal piezoelectric responses, respectively. With an external load of 100 MΩ, the PENG obtained a maximum power density of 0.67 μW/cm². Additionally, the PENG sensor exhibited sensitivity to various human activities and demonstrated high sensitivity and rapid response in monitoring the status of the proposed door lock opening/closing, highlighting its enormous potential in security monitoring applications.