CN110146370B - A kind of loading measuring device and method of tiny force - Google Patents

Abstract

The invention provides a micro-force loading measuring device and a micro-force loading measuring method, which comprise a piezoelectric component, a moving component, a first loading module, a second loading module, a first measuring module and a processing module, wherein the piezoelectric component is arranged on the moving component; the first loading module is used for applying mechanical force to the moving assembly through the deformation of the piezoelectric assembly and driving the moving assembly to move through the mechanical force; the second loading module is used for applying electrostatic force to the moving assembly and driving the moving assembly to move through the electrostatic force; the first measuring module is used for measuring the displacement of the moving component; the processing module is used for obtaining the magnitude of the force borne by the moving component according to the displacement of the moving component, wherein the force comprises the mechanical force, the electrostatic force and the adhesion force, and therefore the coupling measurement of mechanical loading and electric loading is realized.

Description

A kind of loading measuring device and method of tiny force

technical field

The invention relates to the technical field of micro-nano measurement, and more particularly, to a loading measurement device and method for micro-force.

Background technique

With the continuous development of precision instrument technology, scientific research and industrial fields have put forward higher requirements for the characterization of mechanical behavior of materials under micro-mechanical force and micro-electrostatic force. Due to the small size of the micro-nano sample and the range of corresponding force values, it is difficult to load and measure the micro-mechanical force and electrostatic force of the micro-nano sample.

Among them, the loading of micro forces mainly includes mechanical loading and electrical loading. For conductive samples, it is often necessary to measure the mechanical properties and electrical properties of the sample at the same time, that is, to measure the mechanical force and electrostatic force of the sample. Loading and electrical loading cannot be coupled to measure at the same time, which greatly limits the application range.

SUMMARY OF THE INVENTION

In view of this, the present invention provides a loading measuring device and method for a small force, so as to solve the problem of different simultaneous mechanical loading and electrical loading in the prior art.

To achieve the above object, the present invention provides the following technical solutions:

A tiny force loading measurement device, comprising a piezoelectric component, a moving component, a first loading module, a second loading module, a first measurement module and a processing module;

The first loading module is used for controlling the piezoelectric component to generate deformation, and applying a mechanical force to the moving component through the deformation of the piezoelectric component, and driving the moving component to move through the mechanical force;

the second loading module is used for applying electrostatic force to the moving component, and driving the moving component to move by the electrostatic force;

the first measurement module is used to measure the displacement of the moving component;

The processing module is configured to obtain the magnitude of the force borne by the moving component according to the displacement of the moving component, and the force includes the mechanical force and the electrostatic force.

Optionally, an end of the piezoelectric assembly facing the moving assembly carries a sample to be tested, and the piezoelectric assembly is used to drive the sample to be tested to move;

The first end of the moving component is located in the moving direction of the sample to be tested and has a preset distance from the sample to be tested;

The end of the sample to be tested facing the piezoelectric component has a first electrode; the second end of the moving component is fixed and the second end of the moving component has a second electrode, and the second end is connected to the first electrode. One end is relatively set;

The second loading module generates electrostatic force between the first electrode and the second electrode by applying a voltage to the first electrode and the second electrode, and applies the electrostatic force to the moving component superior;

The processing module is further configured to obtain the adhesive force between the moving assembly and the sample to be tested according to the displacement of the moving assembly.

Optionally, further comprising a second measurement module;

the second measurement module is used to measure the displacement of the piezoelectric component;

The processing module is further configured to obtain the deformation amount of the sample to be measured according to the displacement of the piezoelectric component and the displacement of the moving component, and obtain the deformation amount of the sample to be measured and the mechanical force according to the deformation amount of the sample to be measured and the mechanical force. Young's modulus of the sample to be tested.

Optionally, the loading measurement device for the tiny force includes a light source, a first half mirror, a second half mirror, a first mirror to a sixth mirror, and the fifth mirror is located in the between the second piezoelectric component and the sample to be tested, and moves with the piezoelectric component;

the light source is used for emitting measurement light;

The first half mirror is used for dividing the measurement light into a first measurement light and a second measurement light;

the first reflector is used for reflecting the first measurement light to the first end of the moving component;

the second reflector is used for reflecting the first measurement light reflected by the first end of the moving component to the first measurement module;

the third mirror and the fourth mirror are used for reflecting the second measurement light to the second half mirror;

The second half mirror is used for dividing the second measurement light into a third measurement light and a fourth measurement light, reflecting the third measurement light to the fifth mirror, and reflecting the fourth measurement light to the fifth reflection mirror. The measurement light is reflected to the sixth reflection mirror, so that the third measurement light reflected by the fifth reflection mirror interferes with the fourth measurement light reflected by the sixth reflection mirror to form interference light;

The first measurement module is used for the displacement of the first measurement light reflected by the first end of the moving assembly and the pre-obtained correspondence between the displacement of the first measurement light and the displacement of the moving assembly , obtain the displacement of the moving component;

The second measurement module is configured to obtain the displacement of the piezoelectric component according to the fringe number of the interference light and the wavelength of the measurement light.

Optionally, the first measurement module includes a beam quality analyzer and a first calculation module;

The beam quality analyzer is used for measuring the displacement of the first measurement light reflected by the first end of the moving component;

The first calculation module is used for the displacement of the first measurement light reflected by the first end of the moving component and the pre-obtained correspondence between the displacement of the first measurement light and the displacement of the moving component , to obtain the displacement of the moving component.

Optionally, the second measurement module includes a photodetector and a second calculation module;

The photodetector is used to detect the interference light and convert the interference light signal into an electrical signal;

The second calculation module is configured to obtain the fringe number of the interference light according to the electrical signal, and obtain the displacement of the piezoelectric component according to the fringe number and half of the wavelength of the measurement light;

Alternatively, the second measurement module includes a photodetector and an oscilloscope;

The photodetector is used to detect the interference light and convert the interference light signal into an electrical signal;

The oscilloscope is used to obtain a curve of the light intensity of the interference light changing with the voltage according to the electrical signal, so as to obtain the fringe number of the interference light according to the curve, and according to the fringe number and the measurement light Half of the wavelength, the displacement of the piezoelectric component is obtained.

Optionally, it also includes a microscope;

The microscope is used to observe the sample to be tested and the moving assembly.

A loading measurement method for tiny forces, including:

The second loading module applies an electrostatic force to the moving component, and drives the moving component to move through the electrostatic force;

The first measurement module measures the displacement of the moving assembly, and the processing module obtains the electrostatic force according to the displacement of the moving assembly;

The first loading module applies a mechanical force to the moving assembly through the piezoelectric assembly to drive the moving assembly to move;

The first measurement module measures the displacement of the moving component, and the processing module obtains the mechanical force according to the displacement of the moving component.

Optionally, also include:

The first loading module stops working, so that the moving assembly moves in the opposite direction;

The first measurement module measures the displacement of the moving assembly, and the processing module obtains the adhesive force borne by the moving assembly according to the displacement of the moving assembly.

Optionally, also include:

The second measurement module measures the displacement of the piezoelectric component;

The processing module obtains the deformation amount of the sample to be measured carried by the piezoelectric component according to the displacement of the piezoelectric component and the displacement of the moving component, and obtains the deformation amount of the sample to be measured and the mechanical The force yields the Young's modulus of the sample to be tested.

Compared with the prior art, the technical solution provided by the present invention has the following advantages:

In the device and method for loading measurement of tiny force provided by the present invention, the first loading module applies mechanical force to the moving component through the deformation of the piezoelectric component, and drives the moving component to move through the mechanical force, and the second loading module applies electrostatic force to the moving component, And drive the moving component to move through the electrostatic force, the first measurement module measures the displacement of the moving component, and the processing module obtains the magnitude of the mechanical force and electrostatic force according to the displacement of the moving component, thereby realizing the coupled measurement of mechanical loading and electrical loading, expanding the the scope of application of the device.

Description of drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only It is an embodiment of the present invention. For those of ordinary skill in the art, other drawings can also be obtained according to the provided drawings without creative work.

FIG. 1 is a schematic structural diagram of a loading measuring device for tiny force provided by an embodiment of the present invention;

FIG. 2 is a partial structural schematic diagram of a loading measurement device provided by an embodiment of the present invention;

3 is a schematic structural diagram of another micro-force loading measurement device provided by an embodiment of the present invention;

FIG. 4 is a partial structural schematic diagram of another loading measurement device provided by an embodiment of the present invention;

FIG. 5 is a flowchart of a method for measuring loading of a tiny force according to an embodiment of the present invention;

FIG. 6 is a graph of output displacement-driving voltage of piezoelectric ceramics provided by an embodiment of the present invention;

7 is a schematic diagram of a positional relationship between a piezoelectric component and a moving component in an electrostatic force measurement mode provided by an embodiment of the present invention;

FIG. 8 is a graph showing the relationship between capacitance and electrode spacing according to an embodiment of the present invention;

9 is a graph showing the relationship between electrostatic force and electrode spacing according to an embodiment of the present invention;

10 is a schematic diagram of a positional relationship between a piezoelectric component and a moving component in a mechanical force measurement mode provided by an embodiment of the present invention;

FIG. 11 is a schematic diagram of a positional relationship between a piezoelectric component and a moving component in an adhesion measurement mode according to an embodiment of the present invention.

Detailed ways

The above is the core idea of the present invention. In order to make the above objects, features and advantages of the present invention more obvious and easy to understand, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Description, it is obvious that the described embodiments are only some, but not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

An embodiment of the present invention provides a loading measurement device for tiny force, as shown in FIG. 1 , including a piezoelectric component 10, a moving component 11, a first loading module 12, a second loading module 13, a first measurement module 14, and a processing module 15.

Wherein, the first loading module 12 is used to control the deformation of the piezoelectric component 10, and apply a mechanical force to the moving component 11 through the deformation of the piezoelectric component 10, and the moving component 11 is driven to move by the mechanical force; the second loading module 13 is used to move the moving component 11. The component 10 applies electrostatic force, and drives the moving component 11 to move through the electrostatic force; the first measurement module 14 is used to measure the displacement of the moving component 11; the processing module 15 is used to obtain the displacement of the moving component 11 according to the displacement of the moving component 11. The magnitude of the force, which includes mechanical and electrostatic forces.

Optionally, as shown in FIG. 2 , the piezoelectric component 10 in the embodiment of the present invention is a piezoelectric ceramic, and the moving component 11 is a cantilever beam, the first end of the cantilever beam is fixed, and the second end of the cantilever beam moves The ends are located within a distance above the piezoelectric assembly 10 . The first loading module 12 is a first voltage source, and the second loading module 13 is a second voltage source. The processing module 15 includes a computer and the like.

When the second voltage source exerts an electrostatic force on the cantilever beam, that is, in the electrostatic force measurement mode, the moving end of the cantilever beam will move under the action of the electrostatic force. After the first measurement module 14 measures the displacement of the cantilever beam, The processing module 15 obtains the magnitude of the electrostatic force according to the displacement of the cantilever beam.

When the first voltage source applies a voltage to the piezoelectric ceramic, that is, in the mechanical force measurement mode, the piezoelectric ceramic will deform slightly, and the piezoelectric ceramic will move upward. When the moving distance of the piezoelectric ceramic is greater than the distance between the piezoelectric ceramic and the cantilever beam When the distance between them is increased, the piezoelectric ceramic will drive the movable end of the cantilever beam to move together, that is, the piezoelectric ceramic will drive the cantilever beam to move together through the mechanical force generated by its own deformation. After the first measurement module 14 measures the displacement of the cantilever beam, the processing module 15 obtains the magnitude of the mechanical force according to the displacement of the cantilever beam.

Further, as shown in FIGS. 3 and 4 , one end of the piezoelectric assembly 10 facing the moving assembly 11 carries the sample to be tested 20 , and the piezoelectric assembly 10 is used to drive the sample to be tested 20 to move; the first end of the moving assembly 11 is the The moving end is located in the moving direction of the sample to be tested 20 and has a preset distance from the sample to be tested 20 ; the end of the sample to be tested 20 facing the piezoelectric component 10 has the first electrode 16 ; the second end of the moving component 11 is fixed and The second end of the moving component 11 has a second electrode 17, and the second end is opposite to the first end. The second loading module 13 generates electrostatic force between the first electrode 16 and the second electrode 17 by applying a voltage to the first electrode 16 and the second electrode 17 , and applies the electrostatic force to the moving component 11 . The processing module 15 is further configured to obtain the magnitude of the adhesive force between the moving assembly 11 and the sample to be tested 20 according to the displacement of the moving assembly 11 .

That is to say, when the first voltage source applies a voltage to the piezoelectric ceramic, that is, in the mechanical force measurement mode, the piezoelectric ceramic is slightly deformed, and the piezoelectric ceramic drives the sample 20 to be tested and the moving end of the cantilever beam to move together. After that, the first measurement module 14 measures the displacement of the cantilever beam, and the processing module 15 obtains the magnitude of the mechanical force borne by the cantilever beam according to the displacement of the cantilever beam.

When the first voltage source is powered off, in the adhesion measurement mode, the piezoelectric ceramic moves in the opposite direction. At this time, there is adhesion between the sample to be tested 20 and the cantilever beam, and the cantilever is measured by the first measurement module 14. After the displacement of the beam, the processing module 15 obtains the magnitude of the adhesion force between the sample 20 to be tested and the cantilever beam according to the displacement of the cantilever beam.

Optionally, as shown in FIG. 3 , the device for measuring the loading of the minute force in the embodiment of the present invention further includes a second measurement module 18 . The second measurement module 18 is used to measure the displacement of the piezoelectric component 10; the processing module 15 is also used to obtain the deformation of the sample to be measured 20 according to the displacement of the piezoelectric component 10 and the displacement of the moving component 11, and according to the displacement of the piezoelectric component 10 and the displacement of the moving component 11 The amount of deformation of the sample 20 and the mechanical force are used to obtain the Young's modulus of the sample 20 to be tested.

Specifically, the magnitude of the force F can be calculated according to the formula F=-3EIδmoving _component /l ³ , wherein the force F includes mechanical force, electrostatic force and adhesive force, etc. The delta _{moving component} is the displacement of the moving end of the moving component 11, l is the length of the moving component 11, E is the elastic modulus, and I is the moment of inertia.

When the piezoelectric component 10 drives the sample to be tested 20 to squeeze the moving component 11 to apply a mechanical force, since the forces are mutual, the sample to be tested 20 also undergoes slight deformation. That is to say, in the mechanical force measurement mode, the deformation amount δsample of the sample to be measured 20 can be calculated according to the formula _δsample =δpiezoelectric _{component- δmovement component} , where the _{δpiezoelectric component} is the displacement of the piezoelectric component 10 The displacement of the moving _component 11 is the displacement of the moving component 11, that is, the first measurement module 14 obtains the displacement of the moving component 11, and the second measurement module 18 obtains the displacement of the piezoelectric component 10. After the processing module 15 can sample the _sample according to the formula δ = δ _{piezoelectric component} - δ _{moving component} to obtain the deformation amount δ _sample of the sample to be tested 20, according to the formula F = -3EIδ/l ³ to obtain the size of the mechanical force, you can follow the formula E _Young's = (F/S)/ (δ _sample /l) The Young's modulus E _Young's of the sample 20 to be tested is obtained. Wherein, S is the contact area between the sample to be tested 20 and the cantilever beam, and l is the original length of the sample to be tested 20 .

In the embodiment of the present invention, as shown in FIG. 3 , the loading measuring device for the tiny force includes a light source 19 , a first half mirror 210 , a second half mirror 220 , a first mirror 211 , and a second mirror 212, the third reflection mirror 213, the fourth reflection mirror 214, the fifth reflection mirror 215 and the sixth reflection mirror 216, the fifth reflection mirror 215 is located between the piezoelectric component 10 and the sample to be tested 20, such as in the piezoelectric component 10 and the first electrode 16 and move with the piezoelectric component 10 . That is, the amount of movement of the fifth mirror 215 is equal to the amount of movement of the piezoelectric element 10 .

The light source 19 may be a laser light source or the like. The light source 19 is used to emit the measurement light; the first half mirror 210 is used to divide the measurement light into the first measurement light and the second measurement light; the first reflection mirror 211 is used to reflect the first measurement light to the moving component 11. The first end; the second reflector 212 is used to reflect the first measurement light reflected by the first end of the moving assembly 11 to the first measurement module 14; the third reflector 213 and the fourth reflector 214 are used to reflect the second measurement light The light is reflected to the second half mirror 220; the second half mirror 220 is used to divide the second measurement light into the third measurement light and the fourth measurement light, and the third measurement light is reflected to the fifth mirror 215 , the fourth measurement light is reflected to the sixth reflection mirror 216 , so that the third measurement light reflected by the fifth reflection mirror 215 interferes with the fourth measurement light reflected by the sixth reflection mirror 216 to form interference light.

In the embodiment of the present invention, the first measurement module 14 is configured to calculate the displacement of the first measurement light reflected by the first end of the piezoelectric component 10 and the difference between the displacement of the first measurement light obtained in advance and the displacement of the moving component 11 . According to the corresponding relationship, the displacement of the moving component 11 is obtained; the second measurement module 18 is used to obtain the displacement of the piezoelectric component 10 according to the number of fringes of the interference light and half of the wavelength of the measurement light.

Optionally, the first measurement module 14 includes a beam quality analyzer and a first calculation module; the beam quality analyzer is used to measure the displacement of the first measurement light reflected by the first end of the moving assembly 11; the first calculation module uses The displacement of the moving element 11 is obtained according to the displacement of the first measuring light reflected by the first end of the moving element 11 and the pre-obtained correspondence between the displacement of the first measuring light and the displacement of the moving element 11 .

Optionally, the second measurement module 18 includes a photodetector and a second calculation module; the photodetector is used to detect the interference light and convert the interference light signal into an electrical signal; the second calculation module is used to obtain the interference light according to the electrical signal. The amount of displacement of the piezoelectric element 10 is obtained from the number of fringes and half of the wavelength of the measurement light.

Alternatively, the second measurement module 18 includes a photodetector and an oscilloscope; the photodetector is used to detect the interference light and convert the interference light signal into an electrical signal; the oscilloscope is used to obtain a curve of the light intensity of the interference light with the voltage according to the electrical signal, So that the user can obtain the fringe number of the interference light according to the curve, and obtain the displacement of the piezoelectric component 10 according to the fringe number and half the wavelength of the measurement light.

It should be noted that the device for measuring the loading of tiny forces provided by the embodiment of the present invention further includes an optical microscope, which is used to observe the mechanical behavior of the sample to be measured 20 and the moving component 11 and the like.

Specifically, the lens of the optical microscope is located above the first electrode 16 and the second electrode 17, and is used to observe the mechanical behavior of the electrode material under electrostatic force, and to determine the state of contact and desorption between the sample to be tested 20 and the cantilever beam . Alternatively, when electrostatic force and mechanical force are applied, the sample 20 to be tested can be observed in real time through an optical microscope. Of course, before using an optical microscope, you should select an appropriate magnification and adjust the corresponding focal length, which will not be repeated here.

The embodiment of the present invention also provides a loading measurement method for tiny force, as shown in FIG. 5 , including:

S101: The second loading module applies an electrostatic force to the moving component, and drives the moving component to move through the electrostatic force;

S102: The first measurement module measures the displacement of the moving component, and the processing module obtains the electrostatic force according to the displacement of the moving component;

Optionally, referring to FIG. 2 , the piezoelectric component 10 in the embodiment of the present invention is a piezoelectric ceramic, and the moving component 11 is a cantilever beam, the first end of the cantilever beam is fixed, and the second end of the cantilever beam, that is, the moving end, is located at within a certain distance above the piezoelectric assembly 10 . The first loading module 12 is a first voltage source, and the second loading module 13 is a second voltage source. The processing module 15 includes a computer and the like.

When the second voltage source applies an electrostatic force on the cantilever beam, the moving end of the cantilever beam will move under the action of the electrostatic force. After the first measurement module 14 measures the displacement of the cantilever beam, the processing module 15 determines the displacement of the cantilever beam according to the displacement of the cantilever beam. Quantity to get the magnitude of the electrostatic force.

S103: The first loading module applies a mechanical force to the moving component through the piezoelectric component, and drives the moving component to move through the mechanical force;

S104: The first measurement module measures the displacement of the moving component, and the processing module obtains the mechanical force according to the displacement of the moving component.

When the first voltage source applies a voltage to the piezoelectric ceramic, the piezoelectric ceramic will deform slightly, and the piezoelectric ceramic will move upward. When the moving distance of the piezoelectric ceramic is greater than the distance between it and the cantilever beam, the piezoelectric ceramic will move upward. The ceramic will drive the movable end of the cantilever beam to move together, that is, the piezoelectric ceramic will drive the cantilever beam to move together through the mechanical force generated by its own deformation. After the first measurement module 14 measures the displacement of the cantilever beam, the processing module 15 obtains the magnitude of the mechanical force according to the displacement of the cantilever beam.

Optionally, when the piezoelectric component carries the sample to be tested, the method provided by the embodiment of the present invention further includes:

The first loading module stops working, and the moving component moves in reverse;

The first measurement module measures the displacement of the moving assembly, and the processing module obtains the adhesive force between the moving assembly and the sample to be measured according to the displacement of the moving assembly;

When the first voltage source is powered off, the piezoelectric ceramic returns to its original state, that is, moves in the opposite direction. At this time, there is an adhesive force between the sample to be tested and the cantilever beam. After the displacement of the cantilever beam is measured by the first measurement module 14 , the processing module 15 obtains the magnitude of the adhesive force according to the displacement of the cantilever beam.

Optionally, the loading measurement method provided by the embodiment of the present invention further includes:

The second measurement module measures the displacement of the piezoelectric component;

The processing module obtains the deformation amount of the sample to be measured carried by the piezoelectric component according to the displacement of the piezoelectric component and the displacement of the moving component, and obtains the Young's modulus of the sample to be measured according to the deformation amount of the sample to be measured and the mechanical force.

That is to say, in the mechanical force measurement mode, after the first measurement module 14 obtains the displacement of the moving component 11, and the second measurement module 18 obtains the displacement of the piezoelectric component 10, the processing module 15 can obtain the displacement according to the formula _δsample =δ _{Piezoelectric component-} delta _{moving component} obtains the deformation amount delta _sample of the sample to be tested 20, according to the formula F=-3EIδ/l ³ to obtain the size of the mechanical force, you can follow the formula E _Young's = (F/S)/(δ _sample /l) to obtain the Young's modulus E _Young's of the sample 20 to be tested.

Taking the structures shown in Fig. 3 and Fig. 4 as examples, the loading measurement process of the minute force will be described below.

Before performing the micro force measurement, a suitable moving component 11 ie a cantilever beam should be selected according to the range of the required measuring force to ensure that the moving range of the light spot of the first measurement light is within the receiving range of the first measurement module 14 .

Afterwards, the piezoelectric component 10, ie, the piezoelectric ceramic, is gently brought close to the cantilever beam under an optical microscope without causing the cantilever beam to be displaced. Then, by adjusting different voltage values, the piezoelectric ceramics are controlled to achieve different displacements, and the cantilever beams are controlled to achieve different displacements. It should be noted that, at this time, the piezoelectric ceramic needs to be regarded as a rigid body, and the displacement of the piezoelectric ceramic is equal to the displacement of the cantilever beam, then the displacement of the cantilever beam and the movement of the spot of the first measurement light can be established. Correspondence.

The sample 20 to be tested is fixed on the sample stage, and the magnification and working distance of the optical microscope are adjusted, so that the sample 20 to be tested can be clearly imaged. Under the optical microscope, keep the sample 20 to be tested and the cantilever beam parallel, and make the distance between them larger than the required test distance D.

After that, the light source 19 is turned on, the measurement light emitted by the light source 19 is divided into the first measurement light and the second measurement light by the first half mirror 210 , and the first reflection mirror 211 reflects the first measurement light to the first measurement light of the moving assembly 11 . end, the second mirror 212 reflects the first measurement light reflected from the first end of the moving assembly 11 to the first measurement module 14 . The third mirror 213 and the fourth mirror 214 reflect the second measurement light to the second half mirror 220, which divides the second measurement light into the third measurement light and the fourth measurement light , and reflect the third measurement light to the fifth mirror 215 , the fourth measurement light to the sixth mirror 216 , the third measurement light reflected by the fifth mirror 215 and the fourth measurement light reflected by the sixth mirror 216 Light interferes to form interference light.

After that, the first loading module 12 is turned on, that is, the first voltage source is turned on, and the voltage value of the first voltage source is adjusted to make the piezoelectric ceramic move. The graph of the output displacement and driving voltage of the piezoelectric ceramic is shown in FIG. 6 . 6 The upper curve represents the boosting process, and the lower curve represents the bucking process. The displacement of the piezoelectric ceramic is obtained by the second measurement module 18 , so that the distance between the sample to be tested 20 and the cantilever beam reaches the required test distance D.

After that, the second loading module 13 is turned on, that is, the second voltage source is turned on, and the voltage value between the first electrode 16 and the second electrode 17 is set. By applying a voltage to the first electrode 16 and the second electrode 17, the first electrode The electrostatic force between 16 and the second electrode 17 is applied to the cantilever beam located between the first electrode 16 and the second electrode 17, as shown in FIG. move. At this time, the mechanical behavior of the sample to be tested 20 and the like can be observed through an optical microscope.

After the cantilever beam moves, the position of the light spot of the first measurement light reflected by the cantilever beam will also move. The one-to-one correspondence of the amount of movement of the light spot obtains the displacement δ of the cantilever beam to _{move the component} . Afterwards, the processing module 15 can obtain the magnitude of the electrostatic force borne by the cantilever beam according to the formula F=-3EIδ _{moving the component} /l ³ .

It should be noted that there is a constant potential difference V and capacitance C between the first electrode 16 and the second electrode 17 . Capacitance C, electrostatic potential energy W, and electrostatic force F _E are shown in the following equations (1), (2), and (3). where ε is the relative dielectric constant, ε ₀ is the dielectric constant in vacuum, and the change curves of capacitance C and electrostatic force _FE with the distance between the first electrode 16 and the second electrode 17 are shown in FIGS. 8 and 9 .

After that, the second voltage source is turned off, and after the cantilever beam is stabilized, the piezoelectric ceramic is controlled to continue to move by adjusting the first voltage source, so that the piezoelectric ceramic drives the sample to be tested 20 to contact the cantilever arm, but does not make the light of the first measurement light The point is moved, that is, no mechanical force or pressure is applied to the cantilever beam. After that, the first voltage source is continuously adjusted so that the sample 20 to be tested applies mechanical force or pressure to the cantilever beam. As shown in Figure 10, the cantilever beam will move away from the cantilever beam to be measured. The direction of the sample 20 moves.

After the first measurement module 14 collects the position movement of the light spot of the first measurement light, that is, after collecting the position movement of the light spot before and after applying the pressure, according to the displacement of the cantilever beam and the movement of the light spot of the first measurement light The one-to-one correspondence between the quantities obtains the displacement δ of the cantilever beam to _{move the component} . Afterwards, the processing module 15 can obtain the magnitude of the mechanical force or pressure on the cantilever beam according to the formula F=-3EIδmoving _{the component} /l ³ .

After the second measurement module 18 collects the interference light, the displacement amount δ _{piezoelectric component} of the piezoelectric ceramic is obtained according to the fringe number of the interference light and half of the wavelength of the measurement light. The displacement amount δ of the piezoelectric ceramic _component is equal to the number of fringes of the interference light multiplied by half the wavelength of the measurement light. Afterwards, the processing module 15 can calculate the deformation amount δsample of the sample to be tested 20 according to the formula _δsample = _{δpiezoelectric assembly-} δmovement _assembly , and according to the formula E _Young’s =(F/S)/( _δsample /l) The Young's modulus E _Young's of the sample 20 to be tested is obtained. It should be noted that when the piezoelectric ceramic and the fifth reflecting mirror 215 move, the optical path difference between the third measurement light and the fourth measurement light will change, and the number of light and dark fringes of the interference light spot will also change.

After that, the first voltage source is turned off, and the piezoelectric ceramic moves in the opposite direction. As shown in FIG. 11 , the sample to be tested 20 and the cantilever beam are desorbed, and the adhesive force causes the cantilever beam to undergo reverse displacement. The first measurement module 14 collects the After the position movement of the spot of the first measurement light, the displacement δ of the cantilever beam is obtained according to the one-to-one correspondence between the displacement of the cantilever beam and the _movement of the spot of the first measurement light. Afterwards, the processing module 15 can obtain the magnitude of the adhesive force borne by the cantilever beam according to the formula F= ^-3EIδmoving _{the component} /l3.

In the device and method for loading measurement of tiny force provided by the present invention, the first loading module deforms the piezoelectric component, and drives the moving component to move through the mechanical force generated by the deformation of the piezoelectric component, and the second loading module deforms the piezoelectric component. The loading module applies electrostatic force to the moving component, and drives the moving component to move through the electrostatic force, the first measuring module measures the displacement of the moving component, and the processing module is based on the displacement of the moving component The magnitude of the mechanical force and the electrostatic force can be obtained by measuring the size of the mechanical force and the electrostatic force, thereby realizing the coupled measurement of the mechanical loading and the electrical loading, expanding the application range of the device, and effectively solving the problem of measuring the electrostatic force and the mechanical force on different instruments. problems with sample transfer, measurement accuracy differences, and test point variations. Moreover, the micro-force loading measurement device and method provided by the embodiments of the present invention solve the problem of real-time observation of the mechanical behavior of the sample to be tested in situ, and help to link the mechanical and electrical test curves with the actual motion changes of the sample to be tested. stand up.

The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments, and the same and similar parts between the various embodiments can be referred to each other. As 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 part can be referred to the description of the method.

The above description of the disclosed embodiments enables any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (7)

1. A micro-force loading measuring device is characterized by comprising a piezoelectric component, a moving component, a first loading module, a second loading module, a first measuring module, a second measuring module, a processing module, a light source, a first semi-transparent semi-reflective mirror, a second semi-transparent semi-reflective mirror, a first reflector to a sixth reflector, wherein the fifth reflector is positioned between the piezoelectric component and a sample to be measured and moves along with the piezoelectric component;

one end of the piezoelectric component, which faces the moving component, is loaded with a sample to be detected, and the piezoelectric component is used for driving the sample to be detected to move;

the first end of the moving assembly is positioned in the moving direction of the sample to be detected and has a preset distance with the sample to be detected;

one end of the sample to be detected, which faces the piezoelectric component, is provided with a first electrode; the second end of the moving component is fixed and is provided with a second electrode, and the second end is opposite to the first end;

the first loading module is used for controlling the piezoelectric assembly to deform, applying mechanical force to the moving assembly through the deformation, and driving the moving assembly to move through the mechanical force;

the second loading module applies voltage to the first electrode and the second electrode to generate electrostatic force between the first electrode and the second electrode, the electrostatic force is applied to the moving assembly, and the moving assembly is driven to move through the electrostatic force;

the light source is used for emitting measuring light;

the first half mirror is used for dividing the measuring light into first measuring light and second measuring light;

the first reflector is used for reflecting the first measuring light to the first end of the moving component;

the second reflector is used for reflecting the first measuring light reflected by the first end of the moving component to the first measuring module;

the third reflector and the fourth reflector are used for reflecting the second measuring light to the second half mirror;

the second half mirror is used for dividing the second measuring light into third measuring light and fourth measuring light, reflecting the third measuring light to the fifth reflector, and reflecting the fourth measuring light to the sixth reflector, so that the third measuring light reflected by the fifth reflector and the fourth measuring light reflected by the sixth reflector interfere to form interference light;

the first measuring module is used for obtaining the displacement of the moving component according to the displacement of the first measuring light reflected by the first end of the moving component and the corresponding relation between the displacement of the first measuring light and the displacement of the moving component, which is obtained in advance;

the second measuring module is used for obtaining the displacement of the piezoelectric component according to the number of the interference light fringes and the wavelength of the measuring light;

the processing module is used for obtaining the magnitude of a force borne by the moving component according to the displacement of the moving component, wherein the force comprises the mechanical force and the electrostatic force; the processing module is also used for obtaining the adhesive force between the moving component and the sample to be detected according to the displacement of the moving component; the processing module is further used for obtaining the deformation quantity of the sample to be detected according to the displacement quantity of the piezoelectric component and the displacement quantity of the moving component, and obtaining the Young modulus of the sample to be detected according to the deformation quantity of the sample to be detected and the mechanical force.

2. The apparatus of claim 1, wherein the first measurement module comprises a beam quality analyzer and a first calculation module;

the beam quality analyzer is used for measuring and obtaining the displacement of the first measuring light reflected by the first end of the moving component;

the first calculation module is used for obtaining the displacement of the mobile component according to the displacement of the first measuring light reflected by the first end of the mobile component and the corresponding relation between the displacement of the first measuring light and the displacement of the mobile component, wherein the corresponding relation is obtained in advance.

3. The apparatus of claim 2, wherein the second measurement module comprises a photodetector and a second calculation module;

the photoelectric detector is used for detecting the interference light and converting the interference light signal into an electric signal;

the second calculation module is used for obtaining the number of fringes of the interference light according to the electric signal and obtaining the displacement of the piezoelectric component according to the number of the fringes and half of the wavelength of the measuring light;

or, the second measurement module comprises a photoelectric detector and an oscilloscope;

the photoelectric detector is used for detecting the interference light and converting the interference light signal into an electric signal;

the oscilloscope is used for obtaining a curve of the light intensity of the interference light changing along with the voltage according to the electric signal, obtaining the number of fringes of the interference light according to the curve, and obtaining the displacement of the piezoelectric component according to the number of the fringes and half of the wavelength of the measuring light.

4. The apparatus of claim 1, further comprising a microscope;

the microscope is used for observing the sample to be detected and the moving assembly.

5. A micro-force loading measurement method applied to the micro-force loading measurement device according to any one of claims 1 to 4, the measurement method comprising:

the second loading module applies voltage to the first electrode and the second electrode to generate electrostatic force between the first electrode and the second electrode, the electrostatic force is applied to the moving assembly, and the moving assembly is driven to move through the electrostatic force;

the first measuring module obtains the displacement of the moving component according to the displacement of the first measuring light reflected by the first end of the moving component and the corresponding relation between the displacement of the first measuring light and the displacement of the moving component, and the processing module obtains the electrostatic force according to the displacement of the moving component;

the first loading module controls the piezoelectric assembly to deform, applies mechanical force to the moving assembly through the deformation, and drives the moving assembly to move through the mechanical force;

the first measuring module obtains the displacement of the moving component according to the displacement of the first measuring light reflected by the first end of the moving component and the corresponding relation between the displacement of the first measuring light and the displacement of the moving component, wherein the corresponding relation is obtained in advance, and the processing module obtains the mechanical force according to the displacement of the moving component.

6. The method of claim 5, further comprising:

the first loading module stops working, so that the moving assembly moves reversely;

the first measuring module measures the displacement of the moving component, and the processing module obtains the adhesive force born by the moving component according to the displacement of the moving component.

7. The method of claim 5, further comprising:

the second measuring module measures the displacement of the piezoelectric component;

the processing module obtains the deformation quantity of the sample to be tested borne by the piezoelectric component according to the displacement quantity of the piezoelectric component and the displacement quantity of the moving component, and obtains the Young modulus of the sample to be tested according to the deformation quantity of the sample to be tested and the mechanical force.

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