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Piezoelectric materials such as ZnO semiconductors and polyvinylidene fluoride (PVDF) have been extensively studied to produce flexible wearable devices, providing a viable method for energy collection. In this study, PVDF was mixed with ZnO nanoparticles to prepare PVDF/ZnO devices by electrospinning. The composite ZnO affects the diameter of electrospun fibers and the output performance of the devices. As ZnO was added, the diameter of the fibers decreases, but the output current of the devices increases. Moreover, compared with pristine PVDF, the bending output current and pyroelectric current of the devices were improved after mixed with ZnO. The results indicated that PVDF/ZnO composite was a promising flexible device that can provide power for small electronic devices.

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An ultraviolet (UV) sensor consisting of a zinc oxide (ZnO) nanofiber sensing membrane and a quartz crystal microbalance (QCM) was fabricated. ZnO nanofibers were prepared by electrospinning and calcination. The morphology and structure of the nanofiber sensing membrane were characterized by scanning electron microscopy and X-ray diffraction. The QCM sensor based on ZnO nanofibers was found to be sensitive to 254-nm UV light in nitrogen, oxygen and air atmospheres. When the QCM sensor was placed under UV irradiation, the resonant frequency difference rapidly decreased. When the light was removed, the frequency difference recovered until reaching 0 Hz. The stability and repeatability of the proposed ZnO nanofiber-based QCM sensor were demonstrated, and the sensing mechanism was briefly discussed.