Characteristics of Piezoelectric Polymer Film Sensors With Solution-Processable Graphene-Based Electrode Materials

The sensor characteristics of piezoelectric polyvinylidenefluoride (PVDF) sensors with solution-processable electrode materials were studied. The electrodes were solutionprocessed on 28-μm-thick PVDF film. Two graphene-based printable inks, ink-jet, and screen formulated ink, were used. Sensors with evaporated metal electrodes were used as a reference to compare the properties of novel sensor structures. The sensor characteristics studied here were sensitivity, nonlinearity, hysteresis, and the effects of frequency and temperature. The sensor sensitivity measurements revealed mean sensitivities of (31.1 ± 1.4) pC/N for the reference sensors and (26.2 ± 2.2) and (21.4 ± 1.3) pC/N for the sensors with graphene-based ink-jet and screen formulated ink electrodes, respectively. The sensor characteristics of the novel sensors were found to be similar to those of the reference sensors. The new sensors are linear, hysteresis error is negligible, and the operation under changing frequency (up to 100 Hz) is rather stable. Change in ambient temperature somewhat affects the sensor sensitivities. The sensors presented here can be used in several sensing applications, e.g., in plantar pressure distribution measurements.