Giant Piezoelectric Output and Stability Enhancement in Piezopolymer Composites with Liquid Metal Nanofillers

Integrating nanomaterials into the polymer matrix is an effective strategy to optimize the performance of polymer-based piezoelectric devices. Nevertheless, the trade-off between the output enhancement and stability maintenance of piezoelectric composites usually leads to an unsatisfied overall performance for the high-strength operation of devices. Here, by setting liquid metal (LM) nanodroplets as the nanofillers in a poly(vinylidene difluoride) (PVDF) matrix, the as-formed liquid-solid/conductive-dielectric interfaces significantly promote the piezoelectric output and the reliability of this piezoelectric composite. A giant performance improvement featured is obtained with, nearly 1000% boosting on the output voltage (as high as 212 V), 270% increment on the piezoelectric coefficient (d33 & SIM;51.1 pC N-1) and long-term reliability on both structure and output (over 36 000 cycles). The design of a novel heterogenous interface with both mechanical matching and electric coupling can be the new orientation for developing high performance piezoelectric composite-based devices. Liquid metal nanodroplets are introduced into P(VDF-TrFE) matrix to construct a liquid-solid piezoelectric nanocomposite. The optimized liquid metal-PVDF nanocomposites with polar & beta;-phase content of 81.5% demonstrate an impressive piezoelectric coefficient (d33 & SIM;51.1 pC/N) and maximum output voltage of & AP;212 V. The flexible device presented long-term stability and realized the self-powered monitoring and smart analysis of human limbs and facial movements.image