Method and device for measuring static flexoelectric coefficient of long-strip-shaped sample

Abstract

The invention discloses a method and device for measuring the static flexoelectric coefficient of a long-strip-shaped sample, and relates to the technical field of flexoelectric effects.According to the method, the long-strip-shaped sample is forced to generate multi-frequency periodic bending deformation, and meanwhile data of the quantity of electric charges accumulated on an electrode of the long-strip-shaped sample and data of the forced bending distance of the long-strip-shaped sample are collected; the flexoelectric coefficient is calculated through the charge quantity data and the distance data in combination with the flexoelectric effect theory. According to the structure of the device, a clamping part is used for clamping a long-strip-shaped sample; the driving part is used for applying periodic constant-amplitude compression force to the free end of the long-strip-shaped sample; the charge collection part comprises a charge amplifier and a data acquisition card which are sequentially connected with the positive and negative electrodes of the strip-shaped sample through wires; the deformation measuring part comprises a laser range finder for measuring the forced bending micro-displacement of the strip-shaped sample; and the computer is electrically connected with the data acquisition card and the laser range finder. According to the invention, the flexoelectric coefficient is accurately measured by simultaneously measuring the electric charge quantity and the micrometric displacement.

Description

Technical Field

[0001] The present invention relates to the technical field of flexoelectric effect, and more specifically to a method and device for measuring the static flexoelectric coefficient of a long strip sample. Background Art

[0002] The flexoelectric effect exists in any dielectric material, which can have any symmetry. This effect is different from the piezoelectric effect. The piezoelectric effect is limited by symmetry and can only exist in 21 crystal point groups with asymmetric centers. The existing theory of the flexoelectric effect believes that the application of strain gradients will generate polarization charges in dielectric materials, and the polarization charges are proportional to the applied strain gradients. This is the essence of the effect. Due to the wide range of flexoelectric materials, the flexoelectric effect can be used to develop sensors, actuators, transducers, power generation devices, etc.

[0003] In the prior art, the invention patent with application number 201410114668.9 provides a device and method for measuring the flexoelectric coefficient of a gradient-shaped bulk material: the device can only measure gradient bulk materials with a certain stiffness, otherwise, the brittle material will be crushed. In addition, this bulk material needs to be cut into a regular trapezoidal table, otherwise the measurement method will have a large error and make the measurement invalid. This measurement method can only be applied to this strict ideal trapezoidal material, and the universality of this method is limited. The invention patent with application number 201510638757.8 provides a method for measuring the flexoelectric coefficient of a bulk material: the measurement object of this invention is the dynamic flexoelectric coefficient. Unlike the invention patent with application number 201410114668.9, the measurement sample is a larger block square material, and the structural requirements for the material are different from the previous invention. Since the dynamic flexoelectric coefficient is measured, the measurement principle is also different from the previous invention. Neither of these two inventions provides how to accurately measure the deformation of the material. In terms of measuring samples, both inventions are unable to measure the flexoelectric coefficient of thin films, plates, beam structures, or long strip dielectric materials.

[0004] Therefore, accurately measuring the flexoelectric coefficients of various structural materials such as blocks, films, plate beams, etc. is an urgent problem to be solved in this field. Summary of the invention

[0005] In view of this, the present invention provides a method and device for measuring the static flexoelectric coefficient of a long strip sample, aiming to solve the above technical problems.

[0006] In order to achieve the above object, the present invention adopts the following technical solution:

[0007] A method for measuring the static flexoelectric coefficient of a long strip sample: forcing the long strip sample to produce multi-frequency periodic bending deformation, and in this process, simultaneously collecting the charge data accumulated on the long strip sample electrode and the distance data of the forced bending of the long strip sample, and calculating the flexoelectric coefficient through the charge data and distance data combined with the flexoelectric effect theory.

[0008] Preferably, in the above method for measuring the static flexoelectric coefficient of a long strip sample, the positive and negative charges accumulated on the electrodes of the long strip sample are collected and amplified by a charge amplifier.

[0009] Preferably, in the above method for measuring the static flexoelectric coefficient of a long strip sample, the distance is measured by placing a laser rangefinder at the position where the deformation of the long strip sample is the largest.

[0010] Preferably, in the above method for measuring the static flexoelectric coefficient of a long strip sample, the theoretical formula of the flexoelectric effect is: or

[0011] The present invention also provides a device for measuring the static flexoelectric coefficient of a long strip sample, comprising:

[0012] A clamping portion, the clamping portion is used to clamp the long strip sample;

[0013] A driving unit, the driving unit is used to apply a periodic and equal-amplitude compressive force to the free end of the long strip sample;

[0014] A charge collection unit, the charge collection unit comprising a charge amplifier connected to the positive and negative electrodes of the long strip sample through wires, the charge amplifier being electrically connected to a data acquisition card;

[0015] A deformation measuring unit, the deformation measuring unit comprising a laser rangefinder for measuring the micro-displacement of the long strip sample under forced bending;

[0016] A computer is electrically connected to the data acquisition card and the laser rangefinder.

[0017] Preferably, in the above-mentioned device for measuring the static flexoelectric coefficient of a long strip sample, the clamping portion realizes the opening and closing of the clamping jaws through a bolt fastening structure.

[0018] Preferably, in the above-mentioned device for measuring the static flexoelectric coefficient of a long strip sample, the driving part includes a reciprocating electric push rod, a control end of the reciprocating electric push rod is connected to a remote control switch, and the reciprocating electric push rod and the remote control switch are powered by a first DC power supply.

[0019] Preferably, in the above-mentioned device for measuring the static flexoelectric coefficient of a long strip sample, the reciprocating electric push rod is a telescopic rod structure driven by a motor.

[0020] In the measurement of flexoelectric effect, the most difficult problem to solve is the simultaneous accurate measurement of trace charge collection and microscopic deformation. The device uses a reciprocating electric push rod to realize the collection of trace charge and microscopic deformation measurement under multiple identical bends. Through multiple measurements, the problem of inaccurate measurement of microscopic quantities in a few times is reduced, and accidental errors are reduced. According to the basic principle of flexoelectric effect, only by accurately measuring the amount of charge and deformation can the size of the flexoelectric coefficient be relatively accurately derived and calculated, and the flexoelectric properties of a certain dielectric material can be accurately evaluated.

[0021] Preferably, in the above-mentioned device for measuring the static flexoelectric coefficient of a long strip sample, the laser rangefinder is powered by a second DC power supply.

[0022] Preferably, in the above-mentioned device for measuring the static flexoelectric coefficient of a long strip sample, the free end of the long strip sample is located near the middle value of the measurement range of the laser rangefinder.

[0023] It can be known from the above technical solution that, compared with the prior art, the present invention discloses a method and device for measuring the static flexoelectric coefficient of a long strip sample. The present invention can measure the static flexoelectric coefficient of a film, plate or beam structure material, and provides its own measurement principle, physical formula and measurement method. It is completely different from the prior art in terms of measurement principle, measurement sample shape and measurement method. The present invention can measure the flexoelectric coefficient of any long strip dielectric material. According to the device structure and measurement method of the present invention, the trace charge (pC order) generated by the flexoelectric effect can be directly measured, and at the same time, the tiny bending deflection of the material, that is, the tiny deformation amount (μm order) of the sample in the bending direction can be directly and accurately measured. The simultaneous and accurate measurement of the two is the key to ensuring the accuracy of measuring the flexoelectric coefficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0025] Figure 1 The accompanying drawing is a schematic diagram of a device for measuring the static flexoelectric coefficient of a long strip sample provided by the present invention;

[0026] Figure 2 The accompanying drawing is a schematic diagram of a clamping portion provided by an embodiment of the present invention;

[0027] Figure 3 The accompanying drawing is a schematic structural diagram of a reciprocating electric push rod provided in an embodiment of the present invention;

[0028] Figure 4 The accompanying drawing is a schematic structural diagram of a rod body of a reciprocating electric push rod provided in an embodiment of the present invention;

[0029] Figure 5 The accompanying drawing shows a voltage signal collected by a data acquisition card provided by an embodiment of the present invention;

[0030] Figure 6 The accompanying drawings show distance signals collected by a laser rangefinder provided by an embodiment of the present invention;

[0031] Figure 7 The accompanying drawing shows the deflection information obtained by processing the data measured by the laser rangefinder provided in the embodiment of the present invention;

[0032] Figure 8 The accompanying drawings are data analysis diagrams provided by embodiments of the present invention.

[0033] in:

[0034] 1- clamping part;

[0035] 11-upper clamping plate; 12-lower clamping plate; 13-guide rod; 14-bolts and nuts;

[0036] 2- driving part;

[0037] 21-reciprocating electric push rod; 211-mounting frame; 212-driving motor; 213-cam; 214-linear guide seat; 215 rod body; 216 connecting rod; 217-connecting block; 218-pressure block; 219-tightening nut; 22-remote control switch; 23-first DC power supply;

[0038] 3- Charge collection unit;

[0039] 31-charge amplifier; 32-data acquisition card;

[0040] 4- deformation measurement unit;

[0041] 41-laser rangefinder; 42-second DC power supply;

[0042] 5- Computer;

[0043] 6- Long strip samples. DETAILED DESCRIPTION

[0044] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0045] An embodiment of the present invention discloses a method for measuring the static flexoelectric coefficient of an elongated sample: forcing the elongated sample 6 to produce multi-frequency periodic bending deformation, and in this process, simultaneously collecting the charge amount data accumulated on the electrode of the elongated sample 6 and the distance data of the forced bending of the elongated sample 6, and calculating the flexoelectric coefficient through the charge amount data and the distance data in combination with the flexoelectric effect theory.

[0046] In order to further optimize the above technical solution, the positive and negative charges accumulated on the electrodes of the long strip sample 6 are collected and amplified by the charge amplifier 31.

[0047] In order to further optimize the above technical solution, the laser rangefinder 41 is placed at the position where the deformation of the long strip sample 6 is the largest to measure the distance.

[0048] In order to further optimize the above technical solution, the theoretical formula of flexoelectric effect is: or

[0049] See attached Figure 1 In order to implement the above-mentioned method for measuring the static flexoelectric coefficient of a long strip sample, an embodiment of the present invention discloses a device for measuring the static flexoelectric coefficient of a long strip sample, comprising:

[0050] A clamping portion 1, which is used to clamp a long strip sample 6;

[0051] A driving unit 2, the driving unit 2 is used to apply a periodic and equal-amplitude compressive force to the free end of the long strip sample 6;

[0052] A charge collection unit 3, the charge collection unit 3 comprises a charge amplifier 31 connected to the positive and negative electrodes of the long strip sample 6 via wires, and the charge amplifier 31 is electrically connected to a data acquisition card 32;

[0053] The deformation measuring part 4 includes a laser rangefinder 41 for measuring the micro displacement of the long strip sample 6 under forced bending;

[0054] The computer 5 is electrically connected to the data acquisition card 32 and the laser rangefinder 41 .

[0055] See attached Figure 2The clamping part 1 realizes the opening and closing of the clamping jaws through a bolt fastening structure. Specifically, in this embodiment:

[0056] The clamping part 1 includes an upper clamping plate 11 and a lower clamping plate 12, and the long strip sample 6 is clamped between the upper clamping plate 11 and the lower clamping plate 12. The upper clamping plate 11 and the lower clamping plate 12 are guided for vertical displacement by a guide rod 13. The top end of the guide rod 13 is fixed on the back plate of the upper clamping plate 11, and the guide rod 13 passes downward through the back plate of the lower clamping plate 12; the back plates of the upper clamping plate 11 and the lower clamping plate 12 are locked by bolts and nuts 14 to meet the clamping force of the upper clamping plate 11 and the lower clamping plate 12 on the long strip sample 6.

[0057] In addition, in other embodiments, such as performing a simply supported beam structure or four-point bending measurement, the clamping part 1 may not be used, and any simple support platform may be used. It should be noted that the above clamping part structure is a simple structure provided in this embodiment, and other structures may also be made according to requirements, as long as the clamping can be achieved.

[0058] When the cantilever beam is bent, the clamping part 1 with adjustable upper and lower positions can be used to adjust the bending amplitude. The upper and lower distances of the driving part 2 are fixed, so that it can be adjusted left and right to measure the long strip samples 6 of different lengths.

[0059] In order to further optimize the above technical solution, the driving part 2 includes a reciprocating electric push rod 21 , a control end of the reciprocating electric push rod 21 is connected to a remote control switch 22 , and the reciprocating electric push rod 21 and the remote control switch 22 are powered by a first DC power supply 23 .

[0060] In order to further optimize the above technical solution, the reciprocating electric push rod 21 is a telescopic rod structure driven by a motor.

[0061] See attached Figure 3 and attached Figure 4 In this embodiment, the reciprocating electric push rod 21 includes a mounting frame 211, a driving motor 212, a cam 213, a linear guide seat 214, a rod body 215 and a connecting rod 216; the mounting frame 211 is an L-shaped frame as shown in the figure; the driving motor 212 is fixed on the mounting frame 211; the cam 213 is fixedly connected to the power output shaft of the driving motor 212; the linear guide seat 214 is fixed on the mounting frame 211; the rod body 215 passes through the linear guide seat 214 and is slidably connected to the linear guide seat 214, one end of the rod body 215 is connected to a connecting block 217, and the other end is connected to a pressure block 218; the two ends of the connecting rod 215 are rotatably connected to the cam 213 and the connecting block 217 respectively through a pin shaft.

[0062] For the convenience of installation, both ends of the rod body 215 have threads, which are respectively used to be fixedly connected to the connecting block 217 and the pressure block 218, and can also facilitate the adjustment of the extended length of the pressure block 218.

[0063] At the same time, in order to ensure the stability of the pressure block 218 , a tightening nut 219 is threadedly connected, and the tightening nut 219 is pressed against the end surface of the pressure block 218 .

[0064] When the driving motor drives the cam to rotate, the rod body 215 can be driven to perform a linear reciprocating motion along the direction of the guide hole of the linear guide seat 214, thereby applying a periodic and equal-amplitude compressive force to the free end of the long strip sample 6.

[0065] In order to further optimize the above technical solution, the laser rangefinder 41 is powered by a second DC power supply 42 .

[0066] In order to further optimize the above technical solution, the free end of the long strip sample 6 is located near the middle value of the measurement range of the laser rangefinder 41 .

[0067] The purpose of the present invention is to solve the problem of measuring the flexoelectric coefficient of long strip dielectric materials, and to provide a laboratory measurement device with simple structure, low cost, flexible operation and various methods. The device can measure the flexoelectric coefficient of any long strip dielectric material with high accuracy. These measurement methods include cantilever beam bending, simply supported beam bending and four-point bending measurement. All three measurement methods can be completed on the device platform. The device can directly measure the trace charge generated by the flexoelectric effect, and can also directly and accurately measure the bending deflection (micro-displacement) of the material, that is, the deformation amount of the sample in the bending direction. The device achieves the purpose of accurately measuring the flexoelectric coefficient by simultaneously measuring the charge amount and micro-displacement.

[0068] In the device provided in this embodiment, the first DC power supply 23 is connected to the remote control switch 22 and the reciprocating electric push rod 21, and is used to supply power to the motor of the reciprocating electric push rod 21. The remote control switch 22 controls the working state change of the motor.

[0069] The clamping part 1 can be connected to other brackets, such as a bracket that can adjust the position of the clamping part 1 up and down.

[0070] The charge collection unit 3 is composed of a charge amplifier 31 and a data acquisition card 32. The charge amplifier 31 is connected to two electrodes of the long strip sample 6 through a wire, and is used to collect and amplify the trace charge generated by the bending of the sample. At the same time, the charge amplifier 31 transmits the collected charge to the data acquisition card 32 after amplification, and the data acquisition card 32 converts the modal signal into a digital signal and transmits it to the computer 5 for processing.

[0071] The deformation measuring part 4 is composed of a high-precision laser rangefinder 41, which can measure the distance between the laser rangefinder 41 and the long strip sample 6 at a high speed and with high precision. The laser rangefinder 41 is provided with an operating voltage by a second DC power supply 42. At the same time, the laser rangefinder 41 transmits the collected distance signal to the computer 5 for processing.

[0072] In this embodiment, the DC power supply can directly convert 220V AC into 12V or 24V DC, which can power the DC motor and the laser rangefinder 41. The USB interface of the computer 5 can collect digital signals, and the relevant software collects charge voltage and distance signals. According to different measurement methods, the structure of the clamping part 1 can be adjusted.

[0073] The specific working process of the device provided in this embodiment is as follows: first, the driving unit forces the long strip sample 6 to produce periodic bending, and the frequency of bending can be achieved by controlling the rotation speed of the motor. The bending of the long strip sample 6 generates a mechanical strain gradient, and positive and negative charges will accumulate on the electrodes of the long strip sample 6. The charge amplifier 31 collects and amplifies these charges and transmits them to the data acquisition card 32, and then transmits them to the computer 5. In this process, the voltage signal of the charge conversion can be viewed on the computer 5. At the same time, the laser rangefinder 41 is placed at the position where the deformation of the long strip sample 6 is the largest, and the distance is measured with high precision and accuracy. The distance signal measured by the laser rangefinder 41 is transmitted to the computer 5, and the distance signal can also be read on the computer 5. In the process of forced bending of the long strip sample 6, charge collection and amplification are carried out simultaneously with distance measurement. The voltage signal collected by the computer 5 can be converted into charge quantity data according to the multiple of the charge amplifier 31. Through the charge quantity data and distance data, and then according to the relevant theory of the flexoelectric effect, the flexoelectric coefficient can be calculated.

[0074] In this embodiment, the driving part of the device can be reciprocated, so that hundreds or thousands of bending experiments can be realized, which is equivalent to nearly a hundred or a thousand repeated measurements, which can minimize the accidental errors in the experimental process. Secondly, the device uses a high-precision charge amplifier to amplify pC-level charges and solve the problem of difficulty in collecting trace charges. Thirdly, the device uses a high-sampling rate and high-precision laser rangefinder for measuring small distance changes, which can distinguish the measurement of μm-level length changes.

[0075] Embodiment 1:

[0076] Taking the bending of a cantilever beam of a sample as an example, the key signal measurement and acquisition of the device, as well as the processing of signal data are explained:

[0077] During measurement, first turn on the power of the charge amplifier 31 and the data acquisition card 32 to check whether the charge information can be correctly collected and displayed. Since there is no bending of the sample to generate flexural electrical signals, the data collected at this time is a standard periodic sine or cosine signal. Moreover, the signal strength is relatively weak, and the signal strength is uniform and single.

[0078] Then, the power of the laser rangefinder 41 is turned on, and the signal of the measured distance is observed on the computer 5. According to the measuring range of the laser rangefinder 41, the position of the sample needs to be adjusted to near the middle value of the measuring range, so that when measuring, the bending deformation distance is guaranteed not to exceed the measuring range of the laser rangefinder 41. When the sample remains stable, the signal value displayed by the laser rangefinder 41 changes only slightly, while the main value remains constant.

[0079] At this time, the data save button in the signal acquisition software of the data acquisition card 32 and the laser rangefinder 41 is turned on at once, and the background reference signals are first collected and saved. Then the power switch of the driving unit 2 is turned on by the remote control switch, and the driving unit 2 drives the sample to bend continuously. At this time, a peak signal far exceeding the background reference signal can be observed on the data acquisition interface of the data acquisition card 32, and a peak-valley signal far exceeding the reference signal can be observed on the data acquisition interface of the laser rangefinder 41.

[0080] like Figure 5 As shown in the figure, the actual measured charge signal and distance change signal of a piezoelectric organic film are given. The blue curve in the figure shows the voltage or charge signal collected by the device. It can be seen that this measurement was bent 177 times in total. The background reference voltage is 0.02V, and the average value of the measured flexoelectric voltage signal is 0.7586V, and the signal amplitude is 38 times that of the background signal.

[0081] like Figure 6 As shown in the figure, the result diagram of the laser rangefinder measurement value is given. It can be seen from the figure that the data measured this time is relatively accurate and clearly reflects each bending process of the sample. However, such data still needs to remove the background baseline and calculate the deformation variable, that is, the mechanical deflection.

[0082] After being processed by the python software, the following graph reflecting the bending deformation is obtained, as shown in Figure 7 As shown in the figure, the sample has been bent 176 times, and the average bending displacement, that is, the average mechanical deflection is 2.5515mm. The number of bends is exactly the same as the number of peaks in the voltage signal. This shows that the measurement is accurate. According to existing theories:

[0083]

[0084] Where P is the polarization intensity, h is the thickness of the measured sample, L is the length of the sample, δ is the bending deflection of the material, μ eff is the flexoelectric coefficient. In cantilever beam bending, m = 2. In this experiment, the sample length is 2.5 cm, the width is 1 cm, the thickness is 28 μm, the deflection value is 2.5515 mm, the polarization voltage is 0.7586 V, minus the background signal of 0.02 V, the charge is converted to 738.6 pC, and the polarization intensity is calculated to be 295.44 pC / cm 2 To calculate the flexoelectric coefficient, more measurements are needed, and then the plot is made to find the slope. eff The latter expression is regarded as the X-axis, and P is regarded as the Y-axis, then a curve is drawn for linear fitting, and the proportional coefficient of the fitting is the required flexoelectric coefficient. For the bending of the cantilever beam, the following formula can be used:

[0085]

[0086] According to the above formula, after 9 measurements, the data analysis is carried out and we get Figure 8 From this figure, we can see that the flexoelectric coefficient of the material is 0.0024C / m, which proves the feasibility of the experimental equipment.

[0087] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0088] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for measuring the static flexoelectric coefficient of a long strip sample, characterized in that: The long strip sample (6) is forced to produce multi-frequency periodic bending deformation, and in this process, the charge amount data accumulated on the electrode of the long strip sample (6) and the distance data of the forced bending of the long strip sample (6) are collected simultaneously, and the flexoelectric coefficient is calculated by combining the charge amount data and the distance data with the flexoelectric effect theory.

2. A method for measuring the static flexoelectric coefficient of a long strip sample according to claim 1, characterized in that: The positive and negative charges accumulated on the electrodes of the long strip sample (6) are collected and amplified by a charge amplifier (31).

3. The method for measuring the static flexoelectric coefficient of a long strip sample according to claim 1, characterized in that: The distance is measured by placing a laser rangefinder (41) at the position where the deformation of the long strip sample (6) is the largest.

4. A method for measuring the static flexoelectric coefficient of a long strip sample according to claim 1, characterized in that: The theoretical formula of flexoelectric effect is: or 5. A device for measuring the static flexoelectric coefficient of a long strip sample, capable of implementing a method for measuring the static flexoelectric coefficient of a long strip sample as claimed in any one of claims 1 to 4, characterized in that: include: A clamping portion (1), the clamping portion (1) being used to clamp the long strip sample (6); A driving unit (2), the driving unit (2) being used to apply a periodic and equal-amplitude compressive force to the free end of the long strip sample (6); A charge collection unit (3), the charge collection unit (3) comprising a charge amplifier (31) connected to the positive and negative electrodes of the long strip sample (6) via wires, the charge amplifier (31) being electrically connected to a data acquisition card (32); A deformation measuring unit (4), the deformation measuring unit (4) comprising a laser rangefinder (41) for measuring a micro-displacement of the long strip sample (6) under forced bending; A computer (5), wherein the computer (5) is electrically connected to the data acquisition card (32) and the laser rangefinder (41).

6. The device for measuring the static flexoelectric coefficient of a long strip sample according to claim 5, characterized in that: The clamping portion (1) realizes the opening and closing of the clamping jaws through a bolt fastening structure.

7. The device for measuring the static flexoelectric coefficient of a long strip sample according to claim 5, characterized in that: The driving part (2) comprises a reciprocating electric push rod (21), a control end of the reciprocating electric push rod (21) is connected to a remote control switch (22), and the reciprocating electric push rod (21) and the remote control switch (22) are powered by a first direct current power supply (23).

8. The device for measuring the static flexoelectric coefficient of a long strip sample according to claim 7, characterized in that: The reciprocating electric push rod (21) is a telescopic rod structure driven by a motor.

9. The device for measuring the static flexoelectric coefficient of a long strip sample according to claim 5, characterized in that: The laser rangefinder (41) is powered by a second direct current power supply (42).

10. The device for measuring the static flexoelectric coefficient of a long strip sample according to claim 5, characterized in that: The free end of the long strip sample (6) is located near the middle value of the measurement range of the laser rangefinder (41).

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