Design and simulation of curved sensors of PVDF for fetal heart rate monitoring

This paper proposed a highly sensitive micro-force sensor using curved PVDF for fetal heart rate monitoring long-termly. Based on the finite element method, numerical simulations were conducted to compare the straight and curved PVDF films in the aspects of the sensitivity for the dynamic excitation. The results showed that the peak voltages of the sensors varied remarkably with the curvature of the PVDF film. The maximum magnitude of the peak voltage response occurred at a certain value of the curvature. In the experiments, the voltage curves of the sensors were also recorded by an oscilloscope to study the effects of the mass on the surface of the sensors and validate the linearity and sensitivity of the sensors. The results showed that the sensitivity of the sensors up to about 60mV/N, which met the needs of fetal heart rate monitoring.