Ferroelectric nanofibers with nanoconfined tellurium nanobeams for mechanical and thermal energy harvesting and wearable healthcare

Large-area sensing devices open up great potential to trigger continuous self-powering, multifunctional sensors with responses to multiple stimuli. Herein, we report a self-powered flexible hybrid piezo- and pyro-electric nanogenerator (NG) based on Te-reinforced poly(vinylidene fluoride) (PVDF) electrospun nanofibers. It is tested to generate electricity from waste mechanical and thermal energies at room temperature. An electroactive phase (∼94%) is built in along the interface (an electrified jet) of dipoles poled perpendicular to the PVDF backbone '-C-C-' chains. As a proof-of-concept, the fabricated NG generates remarkable electricity, reaching a power density of 4.2 μW cm^-2 under periodic mechanical stimulation, showcasing its potential for the efficient conversion of ambient mechanical energy into electricity. The intrinsic photothermal heat-localization effect of poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) as an organic electrode enhances the pyroelectric response, yielding a pyroelectric coefficient of 40 μC m^-2 K^-1 (which is 4 times higher than that of the undoped fibers), making it capable of detecting low thermal oscillations. Therefore, it has the potential to monitor physiological conditions and body temperature, making it suitable for remote infectious disease surveillance.