Preparation and characterization of UV-cured composite films containing ZnO nanostructures: Effect of filler geometric features on piezoelectric response

[Display omitted] •ZnO nanofillers having a different morphology were synthesized by a facile aqueous sol-gel approach.•The nanofillers were added to a UV-curable acrylic system and photopolymerized.•The presence of ZnO nanostructures turned out to affect the thermal and dynamic-mechanical behavior of the UV-cured films.•The UV-cured composite films showed an interesting piezoelectric behavior both at resonance frequency and at 150Hz. ZnO nanofillers, with different morphologies, were synthesized by a facile aqueous sol-gel approach and embedded, at low concentration (i.e. 4wt.%), into a UV-curable acrylic system. SEM observations showed a homogeneous distribution of the fillers within the cured network. The different morphologies of ZnO nanostructures were found to significantly affect the thermo-oxidative stability and the glass transition temperature of the obtained UV-cured films. Microcantilevers, made of the prepared films with sputtered aluminum contact, were fabricated by using standard microfabrication technology and their piezoelectric response was investigated both at the resonance frequency and at lower frequency values. Despite the low ZnO content, all the UV-cured nanocomposite films showed interesting piezoelectric properties: in particular, the devices containing flower-like nano-structures exhibited the highest root mean square voltage both at 150Hz and at the resonance frequency (about 0.176±0.001 and 0.914±0.001mV, respectively). In addition, these devices also showed maximum peak-peak voltage values at both the selected frequencies.