Original approaches and engineering design tools to fabricate devices in piezoelectric PVDF-based energy harvesting and sensor application.

A novel hybrid piezoelectric structure based on electrospun PVDF NFs and vertically grown ZnO nanorods is presented as a promising nanogenerator to convert mechanical movement more efficiently into electricity for practical applications.

Layered fabric systems with an electrospun nanofiber web layered onto a sandwich of woven fabric were developed to examine the feasibility of developing breathable barrier textile materials. Some parameters of nanofiber mats, including the time of electrospinning and the polymer solution concentration, were designed to change and barrier properties of specimens were compared. Air permeability, water vapor transmission, and water repellency (Bundesmann and hydrostatic pressure tests) were assessed as indications of comfort and barrier performance of different samples. These performances of layered nanofiber fabrics were compared with a well-known water repellent breathable multi-layered fabric (Gortex). Multi-layered electrospun nanofiber mats equipped fabric (MENMEF) showed better performance in windproof property than Gortex fabric. Also, water vapor permeability of MENMEF was in a range of normal woven sport and work clothing. Comparisons of barrier properties of MENMEF and the currently available PTFE coated materials showed that, those properties could be achieved by layered fabric systems with electrospun nanofiber mats.

In recent years, wearable sensors and energy harvesters have shown great potential for a wide range of applications in personalized healthcare, robotics, and human–machine interfaces. Among different types of materials used in wearable electronics, piezoelectric materials have gained enormous attention due to their exclusive ability to harvest energy from ambient sources. Piezoelectric materials can be utilized as sensing elements in wearable sensors while harvesting biomechanical energy. Electrospun piezoelectric polymer nanofibers are extensively investigated due to their high flexibility, ease of processing, biocompatibility, and higher piezoelectric property (in contrast to their corresponding cast films). However, as compared to piezoceramic materials, they mostly exhibit relatively lower piezoelectric coefficients. Therefore, considerable efforts have been devoted to improving the piezoelectricity of electrospun polymer nanofibers recently, resulting in significant advances. This review presents a broad overview of these advances including new material, structure designs as well as new strategies to enhance piezoelectricity of electrospun polymer nanofibers. The challenges in achieving high mechanical performance as well as high piezoelectricity are particularly discussed. The main motivation of this review is to examine these challenges and highlight effective approaches to achieving high‐performance piezoelectric sensors and energy harvesters for wearable technologies.