Study On The Sensing Characteristics Of Piezoelectric Fibers Containing Metal Core On Surface Four Electrode

Metal core piezoelectric fiber is a fibrous piezoelectric sensor, which can mimic hair sensors of insects, and can sense airflow changes of the surround environment or body vibration. Coating 4 pieces of symmetric electrodes on the surface of the piezoelectric fiber sensor with metal core, after polarization, the Multi-electrode metal core piezoelectric fiber (MMPF) sensor was prepared and the cantilever beam structure MMPF airflow sensing model and low frequency vibration sensing model were also established; We arranged the 2 MMPFs into spatial array (MMPF ARRAYS), establishing the spatial array of airflow sensing model, building the experimental platform, and the airflow sensing properties of cantilever beam structure MMPF, low frequency vibration sensing properties and the spatial array were tested to verify the sensing model. It’s main research contents are as follows:(1) Based on the first piezoelectric equation, we established a cantilever beam structure of the MMPF impinging airflow sensing model, namely, under the impact of airflow, the 2 pairs of electrodes on the surface of MMPF will produce electric charge, and the influence of surface electrode distribution angle and fiber length on the performance of the sensor were analyzed; Setting up the experimental system, testing the performance of MMPF cantilever beam on sensing the impinging airflow, and the sensing model was verified. The results showed that a one-dimensional plane of the impinging airflow’s magnitude and direction can be measured by a single MMPF.(2) According to the first piezoelectric equation and the theory of vibration. The charge values of the four surface electrodes were derived when the cantilever beam structure MMPF was under external excitation vibration, and the theoretical model of single MMPF micro vibration sensor was built. Through the analysis of the theoretical model, the effect of the surface electrode distribution angle and the fiber length of a single MMPF on the four electrodes’output charge value were derived. Then the vibration experimental system was built to test a single cantilever beam structure MMPF performance on measuring the impinging vibration response and harmonic vibration response. The results showed that a single MMPF can measure the size and direction of impinging vibration, as well as the harmonic vibration frequency, amplitude and direction.(3) Establishing the theory sensing model of spatial multidimensional metal core piezoelectric electric fiber array (MMPF ARRAYS), the relationship between the 4 pairs of electrodes’ output charge and the airflow velocity was derived. Building the spatial multidimensional metal core piezoelectric electric fiber array airflow sensing experimental platform, and the relationship between the magnitude, direction of the static airflow and the spatial MMPF ARRAYS’output charge was tested, which was validated by experiment.