A highly flexible and substrate-independent self-powered deformation sensor based on massively aligned piezoelectric nano-/microfibers

In this study, we demonstrate highly flexible and substrate-independent piezoelectric nano-/microfiber (NMF) arrays that have the potential to function as a self-powered active deformation sensor. The fabricated hybrid structure of a sensor/power generator (PG) is realized via direct deposition of near-field electrospun and in situ poled polyvinylidene fluoride (PVDF) NMF on a Cu-foil electrode of thickness similar to 200 mu m. The NMF-based active deformation sensor has been successfully deposited on four different flexible substrate materials including paper and fully encapsulated with comparable electrical output performance, demonstrating the superior functionality of substrate-independent deposition of NMF arrays. Capable of integrating into a fabric such as a waving flag due to its high flexibility and excellent conformability, the NMF-based device can serve as an active deformation sensor under ambient wind-speed and the feasibility of efficiently converting the flutter motion into electricity is also demonstrated. This low-cost, simple structure, high sensitivity and good environmentally friendly NMF based PG is a very promising material/technology for practical energy harvesting devices and self-powered sensors and capable of scavenging very small wind power or mechanical induced vibration.