Development of a PVDF Multi-resonance Vibration Sensor with a Wide Range of Frequency Resolution

Abstract

An electromechanical concept in the dynamics of piezoelectric poly-vinylidene fluoride-(PVDF) films is employed to develop a multi-resonance vibration sensor. This real-time sensor has the capability of adjusting its resonant frequency to the ambient vibration frequency. Using only one sensor, we are able to measure the vibration at a wide range of frequencies and overcome many sources of error associated with traditional sensors such as hysteresis, variation in tension and geometry with time, and influence of temperature on electromechanical properties. The equation of motion of piezoelectric films shows that the bias voltage changes the resonant frequencies of the PVDF films significantly. A prototype is built to investigate the effect of the bias voltage on a ribbon PVDF sensor experimentally. Results confirm that the bias voltage also improves the amplitude of vibration, which is proportional to the generated voltage. The proposed sensor is simulated in an FE-software package to study its mechanical performance and electrical output. The results from finite element simulation show excellent agreement with the experimental data.