Abstract

Many applications demonstrated for ZnO desire a high dielectric constant and quickly induced polarization properties with frequency. We present new hollow radial zinc oxide nanostructure and carbon-decorated hollow ZnO heterostructures, which greatly influence the dielectric and capacitive pressure-sensing properties after integrating in polyvinyldine fluoride matrix. The hollow zinc oxide nanostructure was realized by using a simple and cost-effective ambient temperature template-free synthesis process. Crystal structure was investigated by using X-ray diffraction and Raman spectroscopy and then correlated with high-resolution transmission electron microscopy, which reveals buckling of lattice fringes. Mimicking the wurzite structure of ZnO, the developed carbon-decorated hollow radial ZnO improved the dielectric constant similar to 140 at 100 Hz and reinforcing efficiency >4 times that of hollow radial ZnO because of strong interfacial polarization. We demonstrated a simple design, fabrication, and testing of flexible polymer composite pressure-sensing device by using such fascinating nanostructures. The capacitive pressure-sensing response is calculated to be 35 times (= 0.002 MPa) and 24 times (= 0.006 MPa) higher than that of the pristine PVDF-based device after poling under corona. Furthermore, the developed devices showed significant capacitive change upon bending because of the displacement of electrodes and change in spacing between the fillers in the polymer matrix.