Pvdf-based Infrasound Sensor Design

In the acoustic band division, usually sound wave caused by vibrating body at frequency below20Hz is infrasonic wave. Infrasonic wave is commonly found in a variety of industry, transportation, nature and living environment. With the development of modern science and technology, infrasonics has become a new branch of modern acoustics. In recent decades, the detection of infrasound has been made some progress, and some of excellent infrasonic wave sensors have been developed. However, there are some problems. Such as, though capacitive infrasonic wave sensors have been made some progress, its normal work might be affected by vulnerable to additional losses in the high temperature. How to come up with an infrasonic wave sensor which can effectively detect infrasound wave is this study explored.PVDF, as known as polyvinylidene fluoride, a new piezoelectric material of macromolecule with piezoelectric property, high sensitivity, corrosion resistance, wide frequency response, ease of processing, is an ideal sensitive material.This article describes a unique piezoelectric property of PVDF, sensor equation and the equivalent model of PVDF piezoelectric film, discusses the structure and characteristics of PVDF infrasonic wave sensor, material selection, the design of various component parameters, and the process of development.Ultimately a new type of infrasonic wave sensor has been developed. In addition, a new type of infrasonic wave generator has been designed and an infrasonic wave acoustic data acquisition system has been set up. Infrasonic wave caused by infrasonic wave generator can make infrasonic wave sensor produce weak charge change. That charge change can be displayed on the oscilloscope by normalized circuit, high and low pass filtering. Infrasonic wave sensor's frequency error, the linear degree and sensitive indicator has been tested.The test results show that the measurable lower limit frequency of the newly developed infrasonic wave sensor based on PVDF is3Hz. The sensor has the advantages of simple structure, high accuracy in test, light-weight structure and strong anti-jamming capability, which has a high practical value.