Electrospun Well‐Aligned Poly(Vinylidene Fluoride‐Co‐Trifluoroethylene) Nanofiber Membrane for Piezoelectric Sensing

ABSTRACT In recent years, the continuing demand for flexible wearable electronic devices is increasing fast, among which one of the vital points is the design and preparation of products with desired performances and remarkable flexibility. Unfortunately, fabricating ultra‐flexible, wearable, and sensitive piezoelectric sensors and nanogenerators via a facile and cost‐effective technique still remains a tremendous challenge but is highly desired. In this work, a well‐aligned P(VDF‐TrFE) nanofiber membrane was facilely fabricated by the electrospinning process. Subsequently, the structure and properties of the well‐aligned P(VDF‐TrFE) nanofiber membrane were investigated and established a systematic relationship between them. It has been found that the molecular orientation of this membrane along the rotational direction gradually increases upon increasing the rotational speed of the rotating‐drum collector. Furthermore, the piezoelectric nanogenerators (PENG) based on the well‐aligned P(VDF‐TrFE) nanofiber membrane exhibit excellent piezoelectric output performance, sensitivity, long‐term cycling stability, and durability (14,400 cycles), which can be utilized for monitoring human activities under weak to moderate mechanical stimuli (i.e., coughing, finger bending, and walking). This work not only provides a simple and efficient technique to prepare continuous well‐aligned P(VDF‐TrFE) nanofiber membranes with high piezoelectric output, excellent sensitivity, long‐term cycling stability, and durability but also provides a new promising method for wearable pressure sensors.