Mixing nanostructured Ni/piezoPVDF composite thin films with e-beam irradiation: A beneficial synergy to piezoelectric response

Piezoelectric PVDF polymer thin films are nanostructured by swift heavy ion beam resulting in nanoporous structures. The nanocylindars are then partially filled with Ni(0) in order to create a composite of higher dielectric permittivity. In a second step, the composite is irradiated with electron beam, in order to induce chain scissions in the PVDF matrix and render it more flexible. It is found that e-beam irradiation does not affect the remanent polarization up to more than 1MGy. The energy harvesting properties are optimized with a maximum for 1MGy irradiation, delivering an output voltage of 4.1 V.cm⁻² which corresponds to a maximum output power of 25μW. cm^-2 and an integrated power of 0.46μW. cm⁻² for 1 bar of external pressure (mechanical solicitations frequency of 10 Hz). The mechanisms responsible for the enhancement of the harvesting efficiency due to e-beam irradiation are discussed.