Tuning piezoelectric properties of P(VDF-TFE) films for sensor application

Abstract

With the increasing attention in the biomedical field and intelligent wearable devices, flexible piezoelectric materials show a broad space in the field of sensors. Compared with piezoelectric ceramics, polyvinylidene fluoride (PVDF)-based polymers have been widely studied due to their great flexibility. However, the existing materials are expensive and difficult to process, making it difficult to commercial application. Therefore, some attention has been paid to poly(vinylidene fluoride- tetrafluoroethylene) (P(VDF-TFE), F24) for its low cost and great potential in the piezoelectric field. But few reports, especially for sensing applications, have been reported due to the harsh synthesis process in laboratory in the early stage. In this work, the structure and dielectric properties of P(VDF-TFE) copolymers with different TFE contents are systematically studied, and the effect of thermal annealing on their piezoelectric performances are also explored. The results show that F24–20A130 (obtained by solution casting with TFE content of 20 mol% and annealed at 130 °C) exhibits the best piezoelectric properties, and its piezoelectric stress constant (d33) can reach −20 pC/N. Moreover, this sample exhibits excellent response sensitivity in sensing tests and is expected to be used in flexible sensor fields such as healthcare and wearable devices.