Electrospun Polyvinylidene Fluoride Nanogenerator with Hydrophobic Properties and Enhanced Energy Harvesting for Wearable and Wireless Sensing

Polyvinylidene fluoride (PVDF) has better compliance and mechanical processing performance than traditional piezoelectric ceramic materials and is easy to process and mold. However, this also sacrifices part of the piezoelectric properties of PVDF. Therefore, polymer-piezoelectric ceramic composites were developed to balance this problem. Herein, self-polarized PVDF piezoelectric fibers with stable hydrophobicity and improved piezoelectric characteristics were prepared by using a quick and efficient electrostatic spinning process, specifically, dimethoxymethylvinylsilane-modified BaTiO3 (M-BTO) as a piezoelectric enhancer, which improved the dispersion of the filler and the piezoelectricity of the composites. As a result, the output voltage and current of the M-BTO/PVDF composite piezoelectric fiber reached 17.2 V and 421.1 nA, respectively. Moreover, the hydrophobic surface of the composite gives it excellent self-cleaning properties. In view of the excellent electromechanical conversion ability of the composites, the prepared piezoelectric nanogenerator can be used to detect different physiological signals in the human body. A simple wireless system is set up to enable the wireless transmission of piezoelectric signals. This study highlights an interfacial modification approach for the preparation of high-performance piezoelectric energy harvesters, providing a practical and potentially useful basis for human-machine interface applications.