Design, Preparation And Sensing Properties Of Metal Core PVDF Fibers

PVDF is a kind of organic polymer piezoelectric material, which has a direct electromechanical conversion performance and can be used in piezoelectric sensors. In this paper, we used a home-made mould to draw metal core PVDF piezoelectric fiber and prepared partial electrode of metal core piezoelectric fiber sensor (PMPF) and symmetric electrodes of the metal core piezoelectric fiber sensor (SMPF). This paper preliminary studies the airflow sensing property of PMPF and the airflow, vibration sensing properties of SMPF, and certain achievements are obtained. The main research content is as follows:1. Using the home-made mould to successfully draw the metal core PVDF piezoelectric fiber. Photograms of the surface, longitudinal section and cross-section of the fiber were also drawn. The influence on fiber preparation of different metal cores were compared. Analyzing the influence of speed on the the mechanical properties and the content of?.2. Coating partial electrode on the longitudinal surface of the metal core PVDF piezoelectric fiber, after polarization, preparing PMPF sensor, according to the first piezoelectric equation, based on the average charge method, the cantilever beam structure PMPF airflow sensor model was established, and the relationship between the two electrodes'charge of PMPF and the velocity, direction of airflow was derived. Setting up the experimental system, and the performance of cantilever beam structure PMPF on the impinging airflow was verified experimentally. The results showed that the PMPF sensor can measure the direction or velocity of impinging airflow.3. Coating two symmetrical electrodes on the longitudinal surface of the metal core PVDF piezoelectric fiber, after polarization, preparing SMPF sensor, according to the first piezoelectric equation, the cantilever beam structure SMPF airflow sensor model was established, and the relationship between the two electrodes'charge of SMPF and the velocity, direction of airflow was analyzed when the SMPF was under impinging airflow in a uniform flow field. Setting up the experimental system, and the performance of cantilever beam structure SMPF on the impinging airflow was verified experimentally. The results showed that the SMPF sensor can measure the direction or velocity of impinging airflow and has a high sensitivity.4. Based on the first piezoelectric equation and the theory of vibration, cantilever beam structure SMPF vibration sensing theory model was established. When a sinusoidal vibration or impulsive vibration was applied on the fixed end of a cantilever SMPF, the relationship of the two electrodes'charge between vibration amplitude and direction was analyzed. Setting up the experimental system, the cantilever beam structure SMPF's performance on sensing the impact vibration and the harmonic excitation was tested.5. Through the theoretical analysis and experimental research, we can see, the sensing ability of artificial hair sensors PMPF and SMPF in sensing impinging airflow is obvious, and SMPF has an obvious direction sensing properties in sensing impinging vibration and harmonic vibration with the characteristics of small volume, light quality and high sensitivity.