Test method and test device for piezoelectric coefficient of piezoelectric material

Abstract

The invention relates to the technical field of material testing, and provides a test method and a test device for the piezoelectric coefficient of a piezoelectric material. The test method comprises the steps that a pulling force is applied on two opposite sides of a sample to be tested along the extension surface of the sample to be tested; a pulling force signal applied on two opposite sides of the sample to be tested along the extension surface of the sample to be tested is acquired, and an electrical signal between upper and lower electrodes is acquired; a force signal applied on the sample to be tested is determined based on the acquired pulling force signal, and the surface charge density generated by the to-be-tested sample under the pulling force is determined according to the acquired electrical signal; and the piezoelectric coefficient of the sample to be tested is determined based on the determined surface charge density and the determined force signal. The test device and the test method can test the piezoelectric coefficient of a piezoelectric polymer and other materials, and have the advantage of high applicability.

Description

technical field [0001] The invention relates to the technical field of material testing, in particular to a testing method and testing device for piezoelectric coefficients of piezoelectric materials. Background technique [0002] In recent years, due to the widespread use of piezoelectric polymers in more and more fields, the piezoelectric coefficient d of piezoelectric polymers 31 and d 33 The measurement of has increasingly become an important parameter that needs to be characterized. Among them, d 31 It is used to characterize the degree of deformation in the length direction caused by the electric field in the thickness direction, and d 33 It is used to characterize the degree of deformation in the thickness direction caused by the electric field in the thickness direction. [0003] For materials, compared with hard materials such as piezoelectric ceramics, the piezoelectric coefficient d of piezoelectric polymer materials 31 、d 33 The measurement is a relatively ...

AI Technical Summary

Problems solved by technology

[0003] For materials, compared with hard materials such as piezoelectric ceramics, the piezoelectric coefficient d of piezoelectric polymer materials 31 、d 33 The measurement of is a relatively complex process

[0004] Currently used to measure the piezoelectric coefficient d of materials 31 、d 33 The tools are basically designed for hard materials such as piezoelectric ceramics, such as d 33 Measuring instrument (d 33 tester meter, Lianeng Technology Co., Ltd.), impedance analyzer (Keysight E4990 impedance analyzer), etc., when the above tools are used to measure the sample, the size of the sample to be tested is required to be thicker, and the resonant frequency is also required to be low, etc., but , due to the soft mechanical properties of piezoelectric polymers, and the "thicker size", "lower resonance frequency" and so on are not available in piezoelectric polymers, therefore, in the prior art, it is used to measure the piezoelectric coefficient of materials d 31 、d 33 The tools are not suitable for measuring piezoelectric polymers, and the applicability of the test equipment and test methods currently used is low

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