A micro-force measuring device and method

Abstract

The application discloses a micro-force measuring device and method, which comprises a pair of first parallel-plate capacitors and two pairs of second parallel-plate capacitors in a comb structure, two pairs of force-sensitive elements, force-loading probes, a capacitance measuring circuit and a micro-force measuring unit, wherein the first parallel-plate capacitors are variable-distance capacitors, the second parallel-plate capacitors are variable-area capacitors, the capacitance measuring circuit measures the capacitances of the first parallel-plate capacitors and the second parallel-plate capacitors after the force-loading probes are forced to move, and the micro-force measuring unit calculates the movement displacement of the force-loading probes under small-range micro-force measurement and large-range micro-force measurement respectively according to the measured capacitances, and calculates the micro-force under corresponding range micro-force measurement according to the movement displacement and the spring stiffness of the force-sensitive elements. The application has the characteristics of high sensitivity and long service life, and can realize high-precision and large-range testing and force resolution adjustment simultaneously.

Description

Technical Field

[0001] This invention relates to the field of micro-nano scale mechanical testing technology, and in particular to a micro-force measurement device and method. Background Technology

[0002] With the rise of nanoscience and technology, there is an urgent need to develop micro- and nano-scale experimental testing techniques and methods for reliability testing of microelectromechanical systems (MEMS) and mechanical experiments on nanoscale structures or materials. Examples include in-situ testing techniques based on atomic force microscopy (AFM) for tensile, compressive, and bending experiments; in-situ testing techniques based on scanning electron microscopy (SEM) for compressive, bending, and torsion experiments; and in-situ testing techniques based on transmission electron microscopy (TEM) for compressive and bending experiments. The core component of these small-scale mechanical tests is the microforce sensor. Some products are already on the market, such as the FT-S series microforce sensors from FemtoTools in Switzerland. These sensors are fabricated using silicon electronic micromachining technology, allowing for mass production. However, their performance is limited by the brittleness of materials such as silicon and silicon oxide, which restricts the sensor's range and lifespan due to the intrinsic properties of the material, such as strength, toughness, and elastic limits. Furthermore, existing sensors cannot simultaneously achieve high precision and large range testing. Therefore, there is an urgent need to develop a high-performance micro-force sensor made of new materials that has high sensitivity, different measurement modes, can simultaneously achieve high precision and large range testing, and has a long service life. Summary of the Invention

[0003] The present invention aims to at least partially solve one of the technical problems in the related art. Therefore, the first objective of the present invention is to provide a micro-force measuring device that has micro-force measurement modes with large and small ranges, and features high sensitivity and long service life, capable of simultaneously achieving high-precision and large-range testing, as well as force resolution adjustment.

[0004] The second objective of this invention is to provide a method for measuring microforce.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0006] A micro-force measuring device, comprising:

[0007] A pair of first parallel plate capacitors, wherein the pair of first parallel plate capacitors are arranged at a preset interval along the force loading direction, and the pair of first parallel plate capacitors are used to realize small-range micro-force measurement;

[0008] Two pairs of second parallel plate capacitors are respectively disposed above and below the pair of first parallel plate capacitors, and the two pairs of second parallel plate capacitors are used to realize large-range micro-force measurement;

[0009] Two pairs of force-sensitive elements and a force-loading probe are provided. Each pair of force-sensitive elements is disposed between a corresponding pair of second parallel plate capacitors. The force-loading probe is disposed between one pair of force-sensitive elements and connected to the pair of force-sensitive elements. When the force-loading probe is subjected to force and moves along the force loading direction, the capacitance of the pair of first parallel plate capacitors and the two pairs of second parallel plate capacitors changes.

[0010] A capacitance measurement circuit is connected to the pair of first parallel plate capacitors and the two pairs of second parallel plate capacitors respectively, and is used to measure the capacitance of the first parallel plate capacitors and the second parallel plate capacitors after the force-loaded probe moves under force.

[0011] The micro-force measurement unit, connected to the capacitance measurement circuit, is used to calculate the displacement of the force-loaded probe under small-range micro-force measurement and large-range micro-force measurement based on the capacitance of the first parallel plate capacitor and the capacitance of the second parallel plate capacitor, respectively, and to calculate the magnitude of the micro-force under the corresponding range micro-force measurement based on the displacement and the spring stiffness of the force-sensitive element.

[0012] Preferably, the displacement direction of the vertical force loading probe of the first parallel plate capacitor is set, and the displacement direction of the parallel force loading probe of the second parallel plate capacitor is set.

[0013] Preferably, both the first parallel plate capacitor and the second parallel plate capacitor are comb-shaped structures formed by multiple plates facing each other.

[0014] Preferably, when the force-loading probe moves along the direction of the force, the spacing between the plates in the first parallel plate capacitor changes, and the facing area of ​​the plates in the second parallel plate capacitor changes.

[0015] Preferably, both the first parallel plate capacitor and the second parallel plate capacitor are made of amorphous alloy material.

[0016] Preferably, the width of the middle part of each force-sensitive element is greater than the width of its two ends.

[0017] Preferably, the micro-force measuring device is mounted on a substrate, which is a silicon wafer, a ceramic wafer, or a glass wafer.

[0018] To achieve the above objectives, a second aspect of the present invention provides a micro-force measurement method applied to the aforementioned micro-force measurement device, comprising: determining a micro-force measurement mode; connecting a capacitance measurement circuit to a first parallel plate capacitor or a second parallel plate capacitor according to the micro-force measurement mode to perform measurement under the corresponding micro-force measurement mode; detecting the capacitance of the first parallel plate capacitor or the second parallel plate capacitor when a force-loaded probe moves under force; obtaining the correspondence between the capacitance and the displacement of the force-loaded probe, and determining the displacement of the force-loaded probe based on the measured capacitance and the correspondence; and determining the magnitude of the force on the force-loaded probe based on the spring stiffness of the force-sensitive element and the displacement of the force-loaded probe.

[0019] Preferably, the micro-force measurement mode includes a small-range micro-force measurement mode and a large-range micro-force measurement mode.

[0020] Preferably, the end dimension parameters of the force-sensitive element are adjusted to adjust the force measurement resolution of the micro-force measuring device.

[0021] This invention has at least the following technical effects:

[0022] 1. The micro-force measuring device of the present invention includes a pair of first parallel plate capacitors and two pairs of second parallel plate capacitors. Both the first and second parallel plate capacitors are comb-like structures formed by multiple opposing plates. The first parallel plate capacitors are positioned perpendicular to the displacement direction of the force-loading probe, and the second parallel plate capacitors are positioned parallel to the displacement direction of the force-loading probe. Therefore, when the force-loading probe moves along the direction of the force, the spacing between the plates in the first parallel plate capacitors changes, and the facing area of ​​the plates in the second parallel plate capacitors changes. Thus, the first parallel plate capacitors are characterized as variable-pitch capacitors, and the second parallel plate capacitors are characterized as variable-area capacitors. Furthermore, the change in the plate spacing of the variable-pitch capacitors enables small-range micro-force measurement, and the change in the facing area of ​​the plates in the variable-area capacitors enables large-range micro-force measurement. Thus, high-precision and large-range testing can be simultaneously achieved on a single force measuring device through simple circuit switching, providing a solution to the current challenge of balancing range and accuracy in sensors.

[0023] 2. Both the first parallel plate capacitor and the second parallel plate capacitor of the present invention are made of amorphous alloy material. The high hardness, high strength and high elasticity of the amorphous alloy enable the micro-force measuring device to have the advantages of large range and long life.

[0024] 3. In the micro-force measuring device of the present invention, the width of the middle part of each force-sensitive element is greater than the width of the two ends, that is, the ends of the force-sensitive elements are narrowed. The force measurement resolution can be adjusted by adjusting the dimensional parameters of the flexible hinge structure at the ends of the force-sensitive elements, such as the radius of curvature of the flexible hinge, the width of the flexible hinge, and the slenderness ratio of the force-sensitive elements.

[0025] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the micro-force measuring device according to an embodiment of the present invention.

[0027] Figure 2 This is a schematic diagram of the force-sensitive element according to an embodiment of the present invention.

[0028] Figure 3 This is a schematic diagram showing the relationship between the spring stiffness and the dimensional parameters of the flexible hinge in an embodiment of the present invention.

[0029] Figure 4 This is a schematic diagram of the curves of the output force F of the micro-force measuring device according to an embodiment of the present invention and the displacement x of the force-loaded probe tip.

[0030] Figure 5 This is a schematic diagram showing the range of the micro-force measuring device, the size parameters of the flexible hinge, and the relationship between the maximum load and the probe displacement in an embodiment of the present invention.

[0031] Figure 6 This is a flowchart of a micro-force measurement method according to an embodiment of the present invention. Detailed Implementation

[0032] The following describes this embodiment in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the invention, and should not be construed as limiting the invention.

[0033] A micro-force measuring device and method according to this embodiment are described below with reference to the accompanying drawings. Figure 1 This is a schematic diagram of the micro-force measuring device according to an embodiment of the present invention.

[0034] like Figure 1As shown, the micro-force measuring device includes: a pair of first parallel plate capacitors 6, two pairs of second parallel plate capacitors 7, two pairs of force-sensitive elements 5, a force loading probe 4, and multiple second parallel plate capacitor fixing ends 1, multiple first parallel plate capacitor fixing ends 2, multiple force-sensitive element fixing ends 3, as well as a capacitance measuring circuit and a micro-force measuring unit (not shown in the figure). The multiple second parallel plate capacitor fixing ends 1 are used to fix the two pairs of second parallel plate capacitors 7, the multiple first parallel plate capacitor fixing ends 2 are used to fix the one pair of first parallel plate capacitors 6, and the multiple force-sensitive element fixing ends 3 are used to fix the two pairs of force-sensitive elements 5. The micro-force measuring device is insulatedly connected to a substrate, typically such as a silicon wafer, ceramic wafer, or glass wafer, through each fixing end.

[0035] Please continue to refer to this. Figure 1 In this embodiment, a pair of first parallel plate capacitors 6 are arranged at a preset interval along the force loading direction. These first parallel plate capacitors 6 are used to achieve small-range micro-force measurement. Two pairs of second parallel plate capacitors 7 are respectively arranged above and below the pair of first parallel plate capacitors 6, and are used to achieve large-range micro-force measurement. In this embodiment, each pair of force-sensitive elements 5 is disposed between a corresponding pair of second parallel plate capacitors 7. A force loading probe 4 is disposed between one pair of force-sensitive elements 5 and connected to that pair. When the force loading probe 4 is subjected to force and moves along the force loading direction, the capacitance of both the first parallel plate capacitors 6 and the two pairs of second parallel plate capacitors 7 changes.

[0036] It should be noted that in this embodiment, the first parallel plate capacitor 6 is positioned perpendicular to the displacement direction of the force loading probe, and the second parallel plate capacitor 7 is positioned parallel to the displacement direction of the force loading probe. Both the first parallel plate capacitor 6 and the second parallel plate capacitor 7 are comb-shaped structures formed by multiple opposing plates. When the force loading probe 4 moves along the direction of the force, the spacing between the plates in the first parallel plate capacitor 6 changes, and the area of ​​the opposing plates in the second parallel plate capacitor 7 changes.

[0037] Specifically, the first parallel plate capacitor 6 and the second parallel plate capacitor 7 constitute a comb-tooth capacitance testing component, that is, the comb-tooth capacitance testing component is composed of several parallel plate capacitors parallel to and perpendicular to the moving direction of the force-loaded probe 4, wherein the capacitance C of each parallel plate, i.e., the electrode plate, can be obtained by the following formula:

[0038]

[0039] In the above formula, ε is the dielectric constant of the medium between the plates, A is the area of ​​the plates facing each other, and d is the distance between the plates. When the force-loaded probe 4 is subjected to force, the area of ​​the plates facing each other parallel to the direction of movement of the force-loaded probe 4 changes, which is called a variable area capacitor; at the same time, the distance between the plates perpendicular to the direction of movement of the force-loaded probe 4 also changes, which is called a variable distance capacitor. The variable area capacitor and the variable distance capacitor enable this micro-force measuring device to have a large range, low precision measurement mode and a small range, high precision measurement mode. It should be noted that the size parameters of each parallel plate capacitor in this embodiment can also be adjusted according to actual needs. In this embodiment, the area of ​​the plates facing each other can be set to A = 500μm × 60μm.

[0040] Furthermore, such as Figure 2 As shown, the force-sensitive element 5 is a rod that narrows at both ends, meaning its width in the middle is greater than the width at both ends. In this embodiment, all force-sensitive elements 5 are rods of identical dimensions. The narrowing at both ends of each force-sensitive element 5 forms a flexible hinge, and within the elastic range, the force F acting on it and the displacement x in the direction of the force satisfy Hooke's Law:

[0041] F = kx (2)

[0042] In the above formula, k is the spring stiffness of the force-sensitive element 5. Therefore, the magnitude of the micro-force can be determined by the spring stiffness of the force-sensitive element 5 and the displacement of the force-loading probe 4 in the direction of the applied force. Figure 2 In this embodiment, r is the radius of curvature of the flexible hinge, w is the width of the middle part of the force-sensitive element, b is the width of the flexible hinge, and l is the total length of the force-sensitive element 5. In this embodiment, the flexible hinge at the end of the force-sensitive element 5 can be arranged as the four corner points of a parallelogram. Figure 2 (The dashed circle in the middle) is used to achieve large displacement of the force-loaded probe.

[0043] Therefore, in this embodiment, the capacitance of the first parallel plate capacitor 6 and the second parallel plate capacitor 7 after the force-loaded probe 4 moves under force can be measured by a capacitance measurement circuit connected to the first parallel plate capacitor 6 and the second parallel plate capacitor 7 respectively. Then, the displacement of the force-loaded probe 4 under small-range micro-force measurement and large-range micro-force measurement is calculated by the micro-force measurement unit based on the capacitance of the first parallel plate capacitor 6 and the second parallel plate capacitor 7 respectively, and the magnitude of the micro-force under the corresponding range micro-force measurement is calculated based on the displacement and the spring stiffness of the force-sensitive element 5. That is, the load applied by the force-loaded probe 4 can be obtained by multiplying the spring stiffness of the micro-force measurement device and the displacement of the tip of the force-loaded probe 4.

[0044] Optionally, in this embodiment, the one-to-one correspondence between the displacement of the force-loaded probe 4 and the capacitance can be obtained in advance. Since the movement of the force-loaded probe 4 causes one plate of the parallel-plate capacitor connected to it to move, thus changing the comb-tooth capacitance, the capacitance change caused by the displacement of the force-loaded probe 4 can be measured by the capacitance measurement circuit connected to the fixed end of the comb-tooth capacitor and the force-sensitive element 5, thereby establishing a one-to-one correspondence between the displacement of the force-loaded probe 4 and the capacitance. The parallel-plate capacitor parallel to the probe's movement direction is a variable-area capacitor, which can constitute a large-range measurement setting of the micro-force measurement device, while the parallel-plate capacitor perpendicular to the probe's movement direction is a variable-distance capacitor, which can constitute a small-range measurement setting of the micro-force measurement device.

[0045] The switching between the large and small measurement ranges can be achieved as follows: when using the large measurement range, the capacitance measurement circuit is connected... Figure 1 The second parallel plate capacitor fixed terminal 1 and the force-sensitive element fixed terminal 3 are measured. When using the small range measurement setting, the capacitance measurement circuit is connected... Figure 1 Measurements were taken at the fixed end 2 of the first parallel plate capacitor and the fixed end 3 of the force-sensitive element.

[0046] Before measurement, you can select the measurement mode or measurement range. Once the measurement range is selected, the corresponding measurement circuit is turned on, and micro-force measurement can be performed in the corresponding range measurement mode.

[0047] It should be noted that in this embodiment, both the first parallel plate capacitor 6 and the second parallel plate capacitor 7 are made of amorphous alloy material. The high hardness, high strength and high elasticity of amorphous alloy can give the micro-force measuring device the advantages of large range and long life.

[0048] In this embodiment, the spring stiffness of the force-sensitive element 5 can also be adjusted by adjusting the dimensional parameters of the flexible hinge. Figure 3 The relationship between spring stiffness and dimensions is given for some flexible hinge dimensional parameters (b = 10 μm, w = 30 μm in the figure). Figure 4 The output force F of the micro-force measuring device under some flexible hinge dimensional parameters is given as a function of the displacement x of the tip of the force-loaded probe 4.

[0049] Figure 5 The left figure shows the measurement range of the micro-force measuring device under some flexible hinge dimensional parameters. When the load is close to the maximum load, the paradigm equivalent stress of the micro-force measuring device is close to the yield stress of Pt-BMG (amorphous alloy material), which is 1.4 GPa. Figure 5The right figure shows the horizontal displacement of the tip of probe 4 under the maximum load. Additionally, it should be noted that to minimize capacitive coupling between the two sets of plates, the distance between adjacent sets of plates should be four times or more the plate spacing. Furthermore, it should be noted that the micro-force measuring device in this embodiment has a specific loading direction, which is the direction in which the distance between the plates of the variable-distance capacitor in the micro-force measuring device increases.

[0050] With a dielectric constant ε = 8.85 × 10 -12 Taking F / m as an example, with the number of variable area capacitors n1 = 128, the number of variable distance capacitors n2 = 40, and the capacitor plate spacing d = 10μm, the sensitivity S1 of the sensor at the large range measurement setting and the sensitivity S2 of the sensor at the small range measurement setting can be calculated as follows:

[0051]

[0052]

[0053] Therefore, the micro-force measuring device in this embodiment has the advantage of high sensitivity.

[0054] Furthermore, taking the resolution of a typical capacitance measurement circuit as an example, the capacitance resolution of existing capacitance measurement circuits can reach 0.5 fF. Therefore, the smallest resolvable force-load probe displacement for the large range setting is 74 nm, and the smallest resolvable force-load probe displacement for the small range setting is 0.24 nm. Based on... Figure 3 The obtained spring stiffness has a minimum resolvable force of 71.52 N / m × 0.24 nm = 17.16 nN and a maximum range of 13 mN. If the distance between the plates of the parallel plate capacitor is reduced from 10 μm to 5 μm, the resolution can be improved by 4 times to 4.29 nN, while the range remains unchanged.

[0055] Table 1 shows the force measurement resolution and range of micro-force measuring devices with different flexible hinge size parameters.

[0056] Table 1. Force measurement resolution and range of the micro-force measuring device under different flexible hinge size parameters.

[0057]

[0058]

[0059] Therefore, in this embodiment, the force measurement resolution of the micro-force measuring device can be adjusted by adjusting the size parameters of the end of the force-sensitive element 5, i.e., the flexible hinge.

[0060] It should be noted that the above embodiment takes Pt-BMG as an example. If a cobalt-based amorphous alloy with higher yield stress is used, its yield stress can reach ~5GPa. Considering that the test range of the elastic stage is approximately linearly related to the yield stress, it can be deduced that if the material of the micro-force measuring device is replaced by Co-BMG (amorphous alloy material) instead of Pt-BMG, the range can be increased by ~4 times (see Table 1 for details), thus improving the measurement range of the micro-force measuring device.

[0061] Furthermore, the present invention also provides a micro-force measurement method, such as... Figure 6 As shown, the method includes:

[0062] Step S1: Determine the micro-force measurement mode.

[0063] Step S2: Connect the capacitance measurement circuit to the first parallel plate capacitor or the second parallel plate capacitor according to the micro-force measurement mode to perform the measurement under the corresponding micro-force measurement mode.

[0064] Step S3: Detect the capacitance of the first parallel plate capacitor or the second parallel plate capacitor when the force-loaded probe moves under force.

[0065] Step S4: Obtain the correspondence between capacitance and force-loaded probe displacement, and determine the displacement of the force-loaded probe under force movement based on the measured capacitance and the correspondence.

[0066] Step S5: Based on the spring stiffness of the force-sensitive element, determine the magnitude of the force on the force-loading probe by the spring stiffness and the displacement of the force-loading probe.

[0067] Among them, the micro-force measurement mode includes a small-range micro-force measurement mode and a large-range micro-force measurement mode.

[0068] Preferably, the force measurement resolution of the micro-force measuring device can be adjusted by adjusting the end size parameters of the force-sensitive element.

[0069] It should be noted that the specific implementation method of the micro-force measurement method in this embodiment can be found in the specific implementation method of the micro-force measurement device described above.

[0070] In summary, this invention includes a pair of first parallel-plate capacitors and two pairs of second parallel-plate capacitors. Both the first and second parallel-plate capacitors are comb-like structures formed by multiple opposing plates. The first parallel-plate capacitors are positioned perpendicular to the displacement direction of the force-loading probe, while the second parallel-plate capacitors are positioned parallel to the displacement direction of the force-loading probe. Therefore, when the force-loading probe moves along the direction of the force, the spacing between the plates in the first parallel-plate capacitors changes, and the facing area of ​​the plates in the second parallel-plate capacitors changes. Thus, the first parallel-plate capacitors are characterized as variable-pitch capacitors, and the second parallel-plate capacitors are characterized as variable-area capacitors. Furthermore, the change in the plate spacing of the variable-pitch capacitors enables small-range micro-force measurement, while the change in the facing area of ​​the plates in the variable-area capacitors enables large-range... Micro-force measurement allows for simultaneous high-precision and large-range testing on a single force measuring device through simple circuit switching, providing a solution to the challenge of balancing range and accuracy in current sensors. Both the first and second parallel plate capacitors of this invention are made of amorphous alloy material. The high hardness, high strength, and high elasticity of the amorphous alloy give the micro-force measuring device advantages such as a large range and long lifespan. In this invention, the width of the middle section of each force-sensitive element is greater than the width of its two ends, meaning the ends of the force-sensitive elements are narrower. Adjusting the dimensional parameters of the flexible hinge structure at the ends of the force-sensitive elements, such as the radius of curvature and the width of the flexible hinge, allows for adjustment of the force measurement resolution. This invention has the advantages of simple and reliable structure, low cost, high testing accuracy, and a large testing range.

[0071] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0072] Although the present invention has been described in detail through the preferred embodiments above, it should be understood that the above description should not be considered as a limitation of the present invention. Various modifications and substitutions to the present invention will be apparent to those skilled in the art after reading the above. Therefore, the scope of protection of the present invention should be defined by the appended claims.

Claims

1. A micro-force measuring device, characterized in that, include: A pair of first parallel plate capacitors, wherein the pair of first parallel plate capacitors are arranged at a preset interval along the force loading direction, and the pair of first parallel plate capacitors are used to realize small-range micro-force measurement; Two pairs of second parallel plate capacitors are respectively disposed above and below the pair of first parallel plate capacitors, and the two pairs of second parallel plate capacitors are used to realize large-range micro-force measurement; Two pairs of force-sensitive elements and a force-loading probe are provided. Each pair of force-sensitive elements is disposed between a corresponding pair of second parallel plate capacitors. The force-loading probe is disposed between one pair of force-sensitive elements and connected to the pair of force-sensitive elements. When the force-loading probe is subjected to force and moves along the force loading direction, the capacitance of the pair of first parallel plate capacitors and the two pairs of second parallel plate capacitors changes. The first parallel plate capacitor is positioned perpendicular to the displacement direction of the force-loading probe, and the second parallel plate capacitor is positioned parallel to the displacement direction of the force-loading probe. When the force-loading probe moves along the direction of the force, the spacing between the plates in the first parallel plate capacitor changes, and the facing area of ​​the plates in the second parallel plate capacitor changes. The loading direction is the direction in which the distance between the plates of the first parallel plate capacitor increases. A capacitance measurement circuit is connected to the pair of first parallel plate capacitors and the two pairs of second parallel plate capacitors respectively, and is used to measure the capacitance of the first parallel plate capacitors and the second parallel plate capacitors after the force-loaded probe moves under force. The micro-force measurement unit, connected to the capacitance measurement circuit, is used to calculate the displacement of the force-loaded probe under small-range micro-force measurement and large-range micro-force measurement based on the capacitance of the first parallel plate capacitor and the capacitance of the second parallel plate capacitor, respectively, and to calculate the magnitude of the micro-force under the corresponding range micro-force measurement based on the displacement and the spring stiffness of the force-sensitive element.

2. The micro-force measuring device as described in claim 1, characterized in that, The displacement direction of the probe for vertical force loading of the first parallel plate capacitor is set, and the displacement direction of the probe for parallel force loading of the second parallel plate capacitor is set.

3. The micro-force measuring device as described in claim 1, characterized in that, Both the first parallel plate capacitor and the second parallel plate capacitor are comb-shaped structures formed by multiple plates facing each other.

4. The micro-force measuring device as described in claim 1, characterized in that, When the force-loading probe moves along the direction of the force, the spacing between the plates in the first parallel plate capacitor changes, and the facing area of ​​the plates in the second parallel plate capacitor changes.

5. The micro-force measuring device as described in claim 1, characterized in that, Both the first parallel plate capacitor and the second parallel plate capacitor are made of amorphous alloy material.

6. The micro-force measuring device as described in claim 1, characterized in that, The width of the middle part of each force-sensitive element is greater than the width of its two ends.

7. The micro-force measuring device as described in claim 1, characterized in that, The micro-force measuring device is mounted on a substrate, which can be a silicon wafer, a ceramic wafer, or a glass wafer.

8. A micro-force measurement method applied to the micro-force measurement device as described in any one of claims 1-7, characterized in that, include: Determine the micro-force measurement mode; According to the micro-force measurement mode, the capacitance measurement circuit is connected to the first parallel plate capacitor or the second parallel plate capacitor to perform the measurement under the corresponding micro-force measurement mode; The capacitance of the first parallel plate capacitor or the second parallel plate capacitor is detected when the force-loaded probe moves under force. Obtain the correspondence between capacitance and force-loaded probe displacement, and determine the displacement of the force-loaded probe under force movement based on the measured capacitance and the correspondence. The magnitude of the force applied to the force-loading probe is determined by the spring stiffness of the force-sensitive element and the displacement of the force-loading probe under force.

9. The micro-force measurement method as described in claim 8, characterized in that, The micro-force measurement modes include a small-range micro-force measurement mode and a large-range micro-force measurement mode.

10. The micro-force measurement method as described in claim 8, characterized in that, Adjust the end dimension parameters of the force-sensitive element to adjust the force measurement resolution of the micro-force measuring device.

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