Speaker
Description
Energy harvesting devices allowing to recover wasted energy from the environment are increasingly developed. Mechanical energy is the most interesting sources of power for energy harvesting and piezoelectric materials present excellent overall properties for the scavenging of wasted energy. Piezoelectric polymers and, in particular, polyvinylidene fluoride (PVDF), show appropriate mechanical properties for large amplitude movements, higher piezoelectric coefficients, transparency, and be easily integrated into devices. A transparent piezoelectric energy harvesting device has been developed with screen printed transparent (72%) and conductive (42 Ω/sq) electrodes on PVDF sheets with a d33= -33 pC/N, generating about P~12 µW and P~8 µW under pressing and bending modes, corresponding to an energy per cycle of E~ 37 nJ and E~55 nJ, respectively. The piezoelectric energy harvesting characteristics of the materials was theoretical evaluated and the applicability of the materials for touch detection demonstrated.
