阅读说明：本技术 一种压电材料动态压电性能测试系统及方法 (System and method for testing dynamic piezoelectric performance of piezoelectric material ) 是由 朱国栋 杨将 于 2020-12-06 设计创作，主要内容包括：本发明属于仪器仪表技术领域,具体为一种压电材料动态压电性能测试系统及方法。本发明测试系统包括固定架、函数发生器、功率放大器、振动台、数据采集装置、电脑、样品台、动态力传感器、静态力传感器、垂直升降台等部件；本发明集成振动台、数据采集装置、力传感器等组件,依照测试流程,实现不同振幅及频率的力的激励下压电材料压电性能的量化分析。本发明适用于无机压电陶瓷/晶体、压电聚合物、小分子压电体、驻极体、生物压电体等各种压电材料的块体、薄膜及微纳结构。(The invention belongs to the technical field of instruments and meters, and particularly relates to a system and a method for testing dynamic piezoelectric performance of a piezoelectric material. The testing system comprises a fixing frame, a function generator, a power amplifier, a vibration table, a data acquisition device, a computer, a sample table, a dynamic force sensor, a static force sensor, a vertical lifting table and the like; the invention integrates components such as a vibration table, a data acquisition device, a force sensor and the like, and realizes quantitative analysis of piezoelectric performance of piezoelectric materials under excitation of forces with different amplitudes and frequencies according to a test flow. The invention is suitable for the block, the film and the micro-nano structure of various piezoelectric materials such as inorganic piezoelectric ceramics/crystals, piezoelectric polymers, micromolecular piezoelectrics, electrets, biological piezoelectrics and the like.)

1. A piezoelectric material dynamic piezoelectric performance test system is characterized by comprising: the device comprises a fixed frame, a function generator, a power amplifier, a vibration table, a data acquisition device, a computer, a sample table, a dynamic force sensor, a static force sensor and a vertical lifting table; wherein:

the vibration table is fastened on the rigid fixing frame; the electric signal output by the function generator is amplified by a power amplifier and then is input into the vibration table as a driving voltage signal to drive the vibration table to vibrate; the vibration frequency, the amplitude and the vibration form of the vibration table are determined by the frequency, the amplitude and the waveform of the driving voltage signal;

the sample table is rigidly fixed on the vibrating table so as to be driven by the vibrating table to vibrate;

placing a sample to be detected on a sample table; if the sample stage is made of conductive material, an insulating electrical isolation layer can be added between the sample to be measured and the sample stage in order to avoid the conductivity of the sample stage from interfering with the electrical measurement of the sample to be measured;

the vertical lifting platform is fixed on the fixed frame, and the calibrated dynamic force sensor and the calibrated static pressure sensor are fixed at the bottom of the lifting platform; the vertical lifting platform can be controlled to lift manually or electrically so as to press the static pressure sensor, the dynamic force sensor and the sample to be detected onto the sample platform; the static pressure sensor is used for measuring the magnitude of static pressure applied by the vertical lifting platform;

the output signals of the static pressure sensor, the dynamic force sensor and the sample to be detected are respectively monitored by three data acquisition devices (1, 2 and 3), and the data are read and recorded by a computer.

2. The system for testing the dynamic piezoelectric performance of a piezoelectric material according to claim 1, wherein the sample stage is made of various types of metal, ceramic or polymer which is easy to machine and mold; the sample platform is in threaded connection with the vibration platform.

3. The piezoelectric material dynamic piezoelectric performance testing system of claim 1, wherein the static pressure sensor and the dynamic force sensor are calibrated integrated force sensors having both dynamic and static pressure sensing measurement functions.

4. The system for testing the dynamic piezoelectric performance of a piezoelectric material according to claim 1, wherein the structures of the corresponding data acquisition devices are different due to the different types of signals to be measured; specifically, (1) measuring the charge quantity, wherein the data acquisition device comprises a charge amplifier, an electrometer and other equipment; (2) measuring current signals, wherein the data acquisition device comprises an ammeter, a current amplifier and other equipment; (3) measuring voltage signals, wherein the data acquisition device comprises an oscilloscope, a data acquisition card and other equipment; and selecting different data acquisition devices according to different types of the required measurement signals.

5. The system for testing the dynamic piezoelectric performance of a piezoelectric material according to claim 1, wherein the operating frequency is in the range of 0 to 50 kHz.

6. The method for testing the dynamic piezoelectric performance of the piezoelectric material based on the system of any one of claims 1 to 5, is characterized by comprising the following specific steps:

(1) placing a piezoelectric material sample to be detected on a sample table;

(2) circuit connection and power supply start: the vibration table is connected with a function generator through a power amplifier; the static pressure sensor, the dynamic force sensor and the lead of the sample to be detected are respectively connected with the corresponding data acquisition devices, and the data acquisition devices are finally connected with a computer so as to read and store data; turning on the power supplies of the computer, the power amplifier, the function generator and the data acquisition device to enable the equipment to be in a standby state;

(3) static pressure adjustment: the vertical lifting platform is close to a sample to be measured through a manual or electric control device, and finally the static pressure sensor, the dynamic force sensor and the sample to be measured are pressed on the sample platform; monitoring static pressure data detected by a static pressure sensor in real time through a first data acquisition device; the height of the vertical lifting platform is fed back and adjusted until the measured static pressure value reaches a preset value;

(4) dynamic force adjustment: the function generator outputs voltage signals with specific waveforms, specific frequencies and specific amplitudes according to preset parameters, and the voltage signals are amplified by the power amplifier and then drive the vibration table to vibrate; monitoring dynamic force data detected by the dynamic force sensor in real time through a second data acquisition device; adjusting a power amplifier to finally enable the dynamic force amplitude to reach a preset value;

(5) piezoelectric performance testing and analysis: the computer simultaneously reads and records the dynamic force signal monitored by the dynamic force sensor and acquired by the second data acquisition device and the piezoelectric signal output of the sample to be detected and acquired by the third data acquisition device; comparing the dynamic force signal with a piezoelectric signal of a sample to be detected to obtain the piezoelectric performance of a specific frequency and a specific dynamic force amplitude;

(6) and (5) repeating the operations in the steps (3) to (5) to realize the test and analysis of the piezoelectric performance of the sample to be tested under different static pressures, different frequencies and different dynamic force amplitudes.

7. The method for testing the dynamic piezoelectric performance of the system according to claim 6, wherein the piezoelectric material comprises an inorganic piezoelectric ceramic/crystal, a piezoelectric polymer, a small molecular piezoelectric body, an electret or a biological piezoelectric body, and the form of the piezoelectric material is a block, a film or a micro-nano structure.

Technical Field

The invention belongs to the technical field of instruments and meters, and particularly relates to a system and a method for testing dynamic piezoelectric performance of a piezoelectric material.

Background

The piezoelectric material can realize the interconversion between mechanical energy and electric energy, and has been widely applied in the fields of force sensors, micro-energy collectors, transducers, exciters and the like. And various novel high-performance piezoelectric materials are continuously developed and reported, such as lead-free piezoelectric ceramics, flexible piezoelectric materials, biological piezoelectric materials and the like. The piezoelectric material is applied on the basis of the piezoelectric performance, so that the accurate characterization and analysis of the piezoelectric performance is the key for judging the performance of the piezoelectric material and further guiding the development of the high-performance piezoelectric material. The piezoelectric performance characterization which is common at present is mostly obtained under a static or quasi-static condition. The commercial dynamic piezoelectric performance tester is also limited to the test analysis of the piezoelectric performance at 110 Hz. However, the piezoelectric material has a very wide working frequency range, and has application scenarios in a frequency range from quasi-static state to hundreds of megahertz, such as human motion sensing with a frequency of several hertz, sound sensing with a frequency between tens of hertz and thousands of hertz, and ultrasonic application with a frequency of megahertz. The existing piezoelectric performance test products cannot meet the requirement of the piezoelectric performance test of the piezoelectric material in a wide frequency band, and a dynamic piezoelectric performance test system and a test method which are simple and easy to operate and cover a wide frequency band range are urgently needed to be developed.

Disclosure of Invention

The invention aims to provide a system and a method suitable for testing the dynamic piezoelectric performance of a piezoelectric material.

The structure of the dynamic piezoelectric performance test system provided by the invention is shown in the attached figure 1, and the dynamic piezoelectric performance test system comprises: the device comprises a fixed frame, a function generator, a power amplifier, a vibration table, a data acquisition device, a computer, a sample table, a dynamic force sensor, a static force sensor, a vertical lifting table and the like; wherein:

the vibration table is fastened on the rigid fixing frame; the electric signal output by the function generator is amplified by a power amplifier and then is input into the vibration table as a driving voltage signal to drive the vibration table to vibrate; the vibration frequency, amplitude and vibration form of the vibration table are determined by the frequency, amplitude and waveform of the driving voltage signal.

The sample table is rigidly fixed on the vibrating table so as to drive the sample table to vibrate by the vibrating table. The sample stage can be made of various metals (such as aluminum, copper, stainless steel, etc.), ceramics (such as alumina ceramics, etc.), polymers (such as polytetrafluoroethylene, etc.), etc. which are easy to machine and mold. The connection between the sample stage and the vibration stage can be a threaded connection or various other possible rigid connections.

And placing the sample to be detected on a sample table. If the sample stage is made of a conductive material, an insulating electrical isolation layer may be added between the sample to be measured and the sample stage to avoid the conductivity of the sample stage interfering with the electrical measurement of the sample to be measured.

The vertical lifting platform is fixed on the fixed frame, and the calibrated dynamic force sensor (such as a quartz piezoelectric sensor) and the calibrated static pressure sensor (such as a resistance type force sensor) are fixed at the bottom of the lifting platform. And a calibrated integrated force sensor with dynamic and static pressure sensing measurement functions can also be selected. The vertical lifting platform can be controlled to lift manually or electrically so as to press the static pressure sensor, the dynamic force sensor and the sample to be measured onto the sample platform. The static pressure sensor is used for measuring the magnitude of the static pressure applied by the vertical lifting platform.

The output signals of the static pressure sensor, the dynamic force sensor and the sample to be detected are respectively monitored by three data acquisition devices 1, 2 and 3, and the data are read and recorded by a computer.

The structure of the corresponding data acquisition device is different due to the types of the signals (such as electric charge, current and voltage) to be measured. Specifically, (1) measuring the charge quantity, wherein the data acquisition device comprises a charge amplifier, an electrometer and other equipment; (2) measuring current signals, wherein the data acquisition device comprises an ammeter, a current amplifier and other equipment; (3) measuring voltage signals, wherein the data acquisition device comprises an oscilloscope, a data acquisition card and other equipment; and selecting different data acquisition devices according to different types of the required measurement signals.

In the present invention, the operating frequency range is determined by the performance of the vibration table. The method is generally suitable for testing the piezoelectric performance of the piezoelectric material in the frequency range of 0-50 kHz.

In the present invention, if the data acquisition device 3 is a charge amplifier, an electrometer, or the like, for monitoring the charge output of the sample to be measured, the ratio of the measured charge value to the dynamic force value monitored by the corresponding data acquisition device 2 can be used to determine the d of the piezoelectric material₃₃Piezoelectric coefficient.

The piezoelectric performance test of the piezoelectric material by using the test system of the invention comprises the following steps:

(1) placing a sample to be tested: placing a piezoelectric material sample to be detected on a sample table;

(2) circuit connection and power supply start: the vibration table is connected with a function generator through a power amplifier; the static pressure sensor, the dynamic force sensor and the lead of the sample to be detected are respectively connected with the corresponding data acquisition devices, and the data acquisition devices are finally connected with a computer so as to read and store data; turning on the power supplies of the computer, the power amplifier, the function generator and the data acquisition device to enable the equipment to be in a standby state;

(3) static pressure adjustment: the vertical lifting platform is close to a sample to be measured through a manual or electric control device, and finally the static pressure sensor, the dynamic force sensor and the sample to be measured are pressed on the sample platform; monitoring static pressure data detected by a static pressure sensor in real time through a data acquisition device 1; the height of the vertical lifting platform is fed back and adjusted until the measured static pressure value reaches a preset value;

(4) dynamic force adjustment: the function generator outputs a voltage signal with a specific waveform (such as sine, triangle, square wave and any other editable waveform), specific frequency and specific amplitude according to preset parameters, and the voltage signal is amplified by the power amplifier and drives the vibration table to vibrate; monitoring dynamic force data detected by the dynamic force sensor in real time through the data acquisition device 2; adjusting a power amplifier to finally enable the dynamic force amplitude to reach a preset value;

(5) piezoelectric performance testing and analysis: the computer simultaneously reads and records the dynamic force signal monitored by the dynamic force sensor and acquired by the data acquisition device 2 and the piezoelectric signal output of the sample to be detected and acquired by the data acquisition device 3; comparing the dynamic force signal with a piezoelectric signal of a sample to be detected to obtain the piezoelectric performance of a specific frequency and a specific dynamic force amplitude;

(6) and (5) repeating the operations in the steps (3) to (5) to realize the test and analysis of the piezoelectric performance of the sample to be tested under different static pressures, different frequencies and different dynamic force amplitudes.

After the test is finished, the power supply of the equipment is turned off; and (5) heightening the vertical lifting platform and taking out the sample to be measured.

The invention provides a system and a method for testing dynamic piezoelectric performance of a piezoelectric material, which are suitable for piezoelectric materials including but not limited to blocks, films and micro-nano structures of various piezoelectric materials such as inorganic piezoelectric ceramics/crystals, piezoelectric polymers, micromolecular piezoelectrics, electrets, biological piezoelectrics and the like.

Drawings

Fig. 1 is a schematic structural diagram of a dynamic piezoelectric performance testing system.

Fig. 2 is a graph of the charge output of a piezoelectric polymer film at an excitation frequency of 100Hz measured using a dynamic piezoelectricity test system, and the resulting dynamic force curve recorded at the same time.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described with reference to specific examples, which are only a part of the present invention and are not intended to limit the present invention.

Embodiment 1, a specific construction of a dynamic piezoelectric performance test system.

The static pressure sensor is a calibrated film type resistance type pressure sensor, the resistance value is output in a voltage form through the circuit conversion of the sensor, and the corresponding data acquisition device 1 is a four-channel Tak oscilloscope and is connected to the channel 1; the dynamic force sensor is a calibrated quartz force sensor, the detection frequency range is quasi-static to 50KHz, the maximum force born by the dynamic force sensor is 200N, the corresponding data acquisition device 2 is a charge amplifier, and the voltage output of the charge amplifier is connected to a channel 2 of a four-channel Tak oscilloscope; the charge signal of the sample to be detected is monitored by a charge amplifier, and the output of the charge amplifier is connected to a channel 3 in the four-channel Tak oscilloscope. The oscilloscope is connected with a computer, so that data can be conveniently read and recorded. The maximum working frequency of the vibration table is 20 kHz. The function generator can output sine, square, triangular and sawtooth waveforms, the peak-to-peak value of the output voltage signal is 20V, and the highest output frequency is 15 MHz. The maximum output power of the power amplifier is 50 watts. The vertical lifting platform is manually controlled. The sample platform is an aluminum round platform, the diameter of the round platform is 5cm, the thickness of the round platform is 5mm, and the round platform and the vibrating platform are fixed through a screw rod. In order to avoid the interference of the conductivity of the aluminum round table to the test process of the sample to be tested, a layer of insulating polyimide film with the thickness of 50 microns is attached to the round table.

Example 2

In this embodiment, the piezoelectric performance testing system constructed in embodiment 1 is used to measure the charge response output of the piezoelectric polymer P (VDF-TrFE) (vinylidene fluoride-trifluoroethylene copolymer) film at the excitation frequency of 100Hz, and compare the measured charge response output with the dynamic force curve data obtained by simultaneous recording to determine the d of the piezoelectric polymer film at 100Hz₃₃Piezoelectric coefficient; the piezoelectric film is 2 microns thick, and 100nm thick aluminum electrodes are plated on the upper and lower surfaces of the piezoelectric film respectively.

The test flow comprises the following steps:

(1) the piezoelectric polymer film is placed on an aluminum sample table pasted with an insulating polyimide film;

(2) the circuit is connected with and turns on the power supply of the corresponding equipment;

(3) the vertical lifting platform is close to a sample to be tested through manual control, and finally the static pressure sensor, the dynamic force sensor and the sample to be tested are pressed onto the sample platform; simultaneously, observing a static pressure value displayed by the data acquisition device 1 displayed by a computer, and adjusting the vertical lifting platform up and down until the displayed static pressure value reaches a preset value of 2N;

(4) the function generator outputs a sine wave signal with the frequency of 100Hz and the amplitude of 5V, and the signal is amplified by the power amplifier and then applied to the vibration table to drive the sample table to vibrate; adjusting the output power of the power amplifier, and simultaneously observing the dynamic force data displayed by the data acquisition device 2 displayed by the computer until the peak-to-peak value of the dynamic force reaches a preset value 1N;

(5) piezoelectric performance testing and analysis: the computer simultaneously reads and records the dynamic force signal monitored by the dynamic force sensor and acquired by the data acquisition device 2 and the charge signal output of the sample to be detected and read by the data acquisition device 3;

(6) after the test is finished, the power supply of the equipment is turned off; and (5) heightening the vertical lifting platform and taking out the sample to be measured.

The obtained charge response output curve and dynamic force curve of the piezoelectric polymer film are recorded at the same time and are shown in figure 2. The frequency of the two curves is 100Hz, the peak value of the dynamic force is 1N, the corresponding change of the charge output of the piezoelectric film is 31.2pC, and the corresponding d under 100Hz₃₃The piezoelectric coefficient was 31.2 pC/N.