Expected lifetime of fibrous nanogenerator exposed to cyclic compressive pressure.

In this paper, in order to identify the lifetime of energy scavenging devices, the effect of a cyclic compressive load on the performance of polyvinylidene fluoride micro-nano fibrous nanogenerators was investigated, and the electrical output of layers was measured at different cycles and frequencies. Results showed that as the number of cycles increased at the constant frequency, the electrical output initially largely increased and then reached to a maximum level with a very gentle slope. Moreover, the crystalline structure and β -phase of the PVDF nanofibrous mats improved by applying a periodic compressive force. This study showed that, although the PVDF electrospun micro-nano fibers have suitable piezoelectric properties, it is necessary to make some post-treatment to fabricate an energy harvester with constant performance. Results also showed that when the number of cycles at a constant frequency increased, mechanical properties also improved. These results enable us to have an idea about the expected lifetime of a fibrous nanogenerator exposed to cyclic compressive pressure. [ABSTRACT FROM AUTHOR]