Study on the piezoelectric properties of PVDF-EtP nanofiber membranes and its application in pressure sensors

In recent years, polyvinylidene fluoride (PVDF)-based nanofiber membranes have gained significant attention as key materials for applications in sensors, energy harvesters, and flexible electronics due to their excellent piezoelectric properties. However, the piezoelectric performance of PVDF membranes is still limited by their intrinsic structure and material characteristics. Therefore, this study investigates the effect of filler doping on the properties of PVDF nanofiber membranes with the aim of enhancing their piezoelectric performance and stability. Using electrospinning technology, electret particles were incorporated into PVDF nanofiber membranes at different concentrations (e.g., 1wt%, 1.5wt%, and 2wt%). Characterization tests of the composite nanofiber membranes, such as scanning electron microscopy (SEM) and X-ray diffraction (XRD), revealed that the doping of electret particles increased the average fiber diameter and enhanced the β-phase content. In piezoelectric performance tests, the piezoelectric sensors made from electric particle-doped nanofiber membranes showed significant improvement in electrical output under a 20N test pressure. Furthermore, increasing the membrane area and applying higher pressure further enhanced the electrical output. These results indicate that appropriate doping with electric particles can effectively improve the piezoelectric performance of PVDF membranes. Stability tests conducted three months after sensor fabrication demonstrated a significant improvement in the electrical output stability of the piezoelectric sensors containing electric particles. Additionally, an efficient signal processing method was proposed, utilizing an FIR digital low-pass filter to remove high-frequency noise, a smoothing prior method to eliminate baseline drift, and an improved AMPD algorithm to accurately detect the peak position and features of the piezoelectric signal. This method significantly enhanced the stability and accuracy of signal feature extraction. In conclusion, this study presents a simple and effective approach to improving the piezoelectric performance and electrical output stability of PVDF nanofiber membranes through the combination of filler doping and electrospinning technology. This method not only optimizes the properties of PVDF-based composite materials but also provides new insights and technical support for their broad applications in energy harvesting, smart sensors, flexible electronics, and other fields.