Revisiting delta-PVDF based piezoelectric nanogenerator for self-powered pressure mapping sensor

delta-phase comprising polyvinylidene fluoride (PVDF) nanoparticles are fabricated through an electrospray technique by applying a 0.1 MV/m electric field, which is 10(3) times lower than the typical value, required for delta-phase transformation. X-ray diffraction and selected area electron diffraction patterns clearly indicate the delta-phase formation that limits the infrared vibrational spectroscopic technique due to identical molecular chain conformations to that of non-polar alpha-phase. The piezo- and ferro-electric response of delta-PVDF nanoparticles have been demonstrated through a scanning probe microscopic technique based on piezoresponse force microscopy. The localized piezoelectric response, indicated by d(33) coefficient, is found to be similar to-11 pm/V. To utilize the distinct electromechanical response of delta-PVDF nanoparticles, the piezoelectric nanogenerator (PNG) has been fabricated. Due to the stress confinement effect in the spherical shape of delta-PVDF nanoparticles, the PNG exhibits synergistic effect than that of the film-based counterpart. The maximum power, i.e., 930 mu W/m(2) determined by the PNG under similar to 4.5 N of periodic force impact, indicates the potential to use it as a self-powered sensor. As a proof of concept, a self-powered pressure sensor mapping has been demonstrated for representing its realistic technological applicability. Published under an exclusive license by AIP Publishing.