A self-powered flexible hybrid piezoelectric-pyroelectric nanogenerator based on non-woven nanofiber membranes

Self-powered systems based on nanogenerators (NGs) that are capable of harvesting mechanical and thermal energies for electricity and are obtained using low-cost materials and simple preparation methods have received great attention. Herein, we report a lightweight and flexible self-powered hybrid NG based on the piezoelectric and pyroelectric effects of an electrospun non-woven poly(vinylidene fluoride) (PVDF) nanofiber membrane (NFM), which can be directly used as an active layer without any post-poling treatment. The flexibility of the NG was enhanced by using an electrospun thermoplastic polyurethane (TPU) NFM as a substrate and a conductive PEDOT: PSS-PVP NFM and a carbon nanotube layer as the electrodes. The capabilities of the NFM to harvest mechanical and thermal energies were demonstrated. Mechanical impacting and bending can effectively stimulate the piezoelectric output of the NG, which can directly light a LED. Moreover, a hybrid piezoelectric-pyroelectric current of the NG was detected upon simultaneous application of strain and a thermal gradient. Due to its flexible non-woven structure, the NG can further harvest energy from body motion and cold/hot airflows. Furthermore, its mechanical durability, robustness and practicality were investigated by charging a capacitor. The novel design of the NFM-constructed hybrid NG demonstrated here can be applied not only to self-powered wearable electronic textiles but also to power generation on a large scale.