Piezoelectric ceramic driving method for high-speed feedback of AFM system

Abstract

The invention discloses an AFM (atomic force microscope) and a piezoelectric ceramic driving method applied to high-speed feedback of an AFM (atomic force microscope) system, interaction force borne by a probe is enabled to be the same as preset interaction force by controlling the motion depth of piezoelectric ceramic, and the motion depth change of hardness detection piezoelectric ceramic is controlled to accord with a sine curve. Therefore, the movement depth change of the probe is a superposition waveform curve of the movement depth change of the two piezoelectric ceramics. Therefore, surface fluctuation detection and hardness detection of the to-be-detected surface are realized. According to the invention, the motion depth changes of the two piezoelectric ceramics are controlled to be non-interfering motion depth changes, so that the motion depth change (i.e., sinusoidal vibration) for detecting the viscosity of the surface to be detected and the motion depth change for feedback tracking of the appearance of the surface to be detected are two non-interfering motion depth changes. And the stroke of feedback tracking of the to-be-measured surface topography is ensured. Therefore, under the condition that the scanning speed of the atomic force microscope is high, a sample with large surface fluctuation can be measured.

Description

Technical Field

[0001] This invention relates to surface property testing technology, and more particularly to a piezoelectric ceramic driving method for high-speed feedback in AFM systems. Background Technology

[0002] Atomic force microscopy (AFM) boasts advantages such as high resolution and wide applicability, making it a crucial tool for micro / nano-scale morphology characterization, property measurement, and micro / nano-scale manipulation. Among these, the non-resonant tapping mode, an important operating mode of AFM, has received significant attention and application in recent years for characterizing soft matter samples and complex surfaces.

[0003] In the non-resonant tapping mode, the probe cantilever beam vibrates at a frequency below its resonant frequency. This vibration mode avoids the unstable contact between the probe and the sample caused by high-frequency vibration in the traditional resonant tapping mode, while ensuring that the probe contacts and separates from the sample surface multiple times in each vibration cycle. By accurately recording the forces between the probe and the sample, the probe amplitude and displacement can be further adjusted to achieve precise measurement of the mechanical properties of the sample surface.

[0004] However, in non-resonant tapping mode, the piezoelectric ceramic needs to both drive the probe to vibrate sinusoidally and respond rapidly to changes in the height of the probe relative to the sample's surface for morphology tracking. This dual function significantly limits the travel of the piezoelectric ceramic, especially in high-speed scanning and measurements of samples with large surface undulations. The travel of the piezoelectric ceramic for sinusoidal vibration occupies most of its displacement space, making it difficult to simultaneously handle sinusoidal motion and feedback tracking of the sample's surface morphology, thus affecting the measurement range and accuracy.

[0005] Therefore, how to solve the problem of measuring samples with large surface undulations using atomic force microscopy at high scanning speeds has become a pressing technical issue that the industry needs to address. Summary of the Invention

[0006] This invention provides a piezoelectric ceramic driving method for high-speed feedback in AFM systems, aiming to solve the technical problem of measuring samples with large surface undulations in atomic force microscopes at high scanning speeds.

[0007] According to a first aspect of the present invention, an embodiment of the present invention provides a module comprising: a probe, a piezoelectric ceramic, a deformation detection module, and a control module;

[0008] The piezoelectric ceramic is connected to the probe and controls the probe to move perpendicular to the first plane. The piezoelectric ceramic includes a first deformation force control piezoelectric ceramic and a softness and hardness detection piezoelectric ceramic connected in sequence.

[0009] The deformation detection module is coupled to the input terminal of the control module and is used to detect the deformation of the probe and output a detection signal.

[0010] The control module receives the detection signal at its input terminal and its output terminal is respectively coupled to the control terminal of the first deformation force control piezoelectric ceramic and the control terminal of the soft and hardness detection piezoelectric ceramic.

[0011] The control module is configured to: acquire the interaction force received by the probe based on the detection signal, and output a first control signal to the control terminal of the first deformation force-controlled piezoelectric ceramic based on the interaction force, so as to control the change in the movement depth of the piezoelectric ceramic, making the interaction force received by the probe the same as the preset interaction force; and

[0012] A second control signal is output to the control terminal of the soft and hardness detection piezoelectric ceramic, so that the change in the motion depth of the soft and hardness detection piezoelectric ceramic conforms to a sine curve, and the change in the motion depth of the probe is a superimposed waveform curve. The superimposed waveform curve is the superposition of the curve corresponding to the change in motion depth of the first deformation force control piezoelectric ceramic 102 and the curve corresponding to the change in motion depth of the soft and hardness detection piezoelectric ceramic.

[0013] Optionally, the preset interaction force includes a preset suspension interaction force and a preset contact interaction force;

[0014] The method for controlling the interaction force on the probe to be the same as the preset interaction force includes:

[0015] The suspended interaction force experienced by the probe is controlled to be the same as the preset suspended interaction force; and

[0016] The contact interaction force applied to the probe is controlled to be the same as the preset contact interaction force.

[0017] Optionally, the preset interaction force has a preset force range, and the piezoelectric ceramic further includes: a second deformation force control piezoelectric ceramic;

[0018] The output terminal of the control module is coupled to the control terminal of the second deformation force control piezoelectric ceramic, and the second deformation force control piezoelectric ceramic is connected to the first deformation force control piezoelectric ceramic 102.

[0019] The control module is further configured to: acquire the interaction force received by the probe based on the detection signal; and when the interaction force exceeds the preset force range, output a third control signal to the control end of the second deformation force control piezoelectric ceramic based on the interaction force, so as to control the distance between the probe and the first plane, so that the interaction force received by the probe is within the preset force range.

[0020] Optionally, the atomic force microscope also includes a sample stage;

[0021] The sample stage is used to provide the first plane, on the surface of the first plane, on which a sample is placed. The probe is used to contact the surface of the sample to be tested in order to detect the morphology of the sample.

[0022] Optionally, the probe includes a cantilever beam and a needle tip located at a first end of the cantilever beam, a second end of the cantilever beam being coupled to the piezoelectric ceramic, the cantilever beam having a first angle with the first plane, and the needle tip being perpendicular to the first plane.

[0023] Optionally, the atomic force microscope also includes a probe clip for connecting the second end of the cantilever beam to the piezoelectric ceramic.

[0024] Optionally, the deformation detection module includes a laser emitting unit and a position detection unit;

[0025] The laser emitting unit, the position detection unit, and the cantilever beam are all located on the same side of the first plane, and the height of the laser emitting unit and the position detection unit from the first plane is greater than the height of the cantilever beam from the first plane. The output terminal of the position detection unit is coupled to the input terminal of the control module.

[0026] The laser emitting unit is used to emit laser light toward the cantilever beam;

[0027] The input terminal of the position detection unit receives the reflected beam of the laser, and the position detection unit is used to obtain the deformation of the probe based on the reflected beam and output the detection signal.

[0028] According to a second aspect of the present invention, embodiments of the present invention provide a piezoelectric ceramic driving method for high-speed feedback in an AFM system, applicable to any of the above-mentioned atomic force microscopes, the method comprising:

[0029] The deformation of the probe is detected, and a detection signal is output.

[0030] The interaction force experienced by the probe is obtained based on the detection signal, and a first control signal is output to the control end of the first deformation force-controlled piezoelectric ceramic based on the interaction force, so as to control the movement depth of the piezoelectric ceramic, making the interaction force experienced by the probe the same as the preset interaction force; and

[0031] A second control signal is output to the control terminal of the soft and hardness detection piezoelectric ceramic, so that the change in the motion depth of the soft and hardness detection piezoelectric ceramic conforms to a sine curve, and the change in the motion depth of the probe is a superimposed waveform curve, which is the superposition of the curve corresponding to the change in motion depth of the first deformation force control piezoelectric ceramic and the curve corresponding to the change in motion depth of the soft and hardness detection piezoelectric ceramic.

[0032] Optionally, a method for controlling the interaction force experienced by the probe to be the same as a preset interaction force includes:

[0033] The suspended interaction force experienced by the probe is controlled to be the same as the preset suspended interaction force; and

[0034] The contact interaction force applied to the probe is controlled to be the same as the preset contact interaction force.

[0035] Optionally, the method further includes:

[0036] The interaction force on the probe is obtained based on the detection signal. When the interaction force exceeds the preset force range, a third control signal is output to the control terminal of the second deformation force control piezoelectric ceramic based on the interaction force to control the distance between the probe and the first plane, so that the interaction force on the probe is within the preset force range.

[0037] Compared with the prior art, the technical solution of the embodiments of the present invention has the following beneficial effects:

[0038] This invention discloses an atomic force microscope (AFM). By controlling the movement depth of the piezoelectric ceramics, the interaction force experienced by the probe is made the same as the preset interaction force. Furthermore, the change in the movement depth of the hardness-detecting piezoelectric ceramics is controlled to conform to a sinusoidal curve, resulting in a waveform curve of the probe's movement depth changes being a superposition of the movement depth changes of the two piezoelectric ceramics. This enables the detection of surface undulations and hardness of the surface under test. By separately controlling the movement depth changes of the two piezoelectric ceramics to be independent, this invention ensures that the movement depth changes for detecting the viscosity of the surface under test (i.e., sinusoidal vibration) and the movement depth changes for feedback tracking of the surface morphology are two independent movement depth changes. This ensures that the stroke of the sinusoidal vibration does not occupy the stroke of the feedback tracking of the surface morphology. Therefore, this allows the AFM to measure samples with large surface undulations even at high scanning speeds.

[0039] Furthermore, the present invention also controls the interaction force on the probe within the preset interaction force range when the interaction force on the probe exceeds the preset force range (i.e., the undulation of the surface to be measured exceeds the preset range), thereby coarsely adjusting the distance between the probe and the surface to be measured, so that the atomic force microscope can measure samples with greater surface undulation. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0041] Figure 1 This is a schematic diagram of the structure of the atomic force microscope in the first embodiment of the present invention;

[0042] Figure 2 This is a schematic diagram of the atomic force microscope in the second embodiment of the present invention;

[0043] Figure 3 This is a schematic diagram of the atomic force microscope in the third embodiment of the present invention;

[0044] Figure 4 This is a schematic diagram of the structure of the atomic force microscope in the fourth embodiment of the present invention;

[0045] Figure 5 This is a schematic diagram of the atomic force microscope in the fifth embodiment of the present invention;

[0046] Figure 6 This is a schematic flowchart of the piezoelectric ceramic driving method for high-speed feedback in the AFM system of the present invention. Detailed Implementation

[0047] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0048] The terms “first,” “second,” “third,” “fourth,” etc. (if present) in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a particular order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0049] The technical solution of the present invention will be described in detail below with reference to specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments.

[0050] As described in the background section, how to measure samples with large surface undulations using atomic force microscopy at high scanning speeds has become a pressing technical problem in the industry. The following explanation will be provided in conjunction with the accompanying drawings.

[0051] In existing technologies, atomic force microscopy (AFM) includes a piezoelectric ceramic and a sample stage. This microscope is used to measure the morphology and hardness of the sample surface. The piezoelectric ceramic is responsible for adjusting the displacement perpendicular to the sample stage based on the probe's deformation, ensuring that the probe maintains a consistent amount of deformation during detection. This means that the contact force between the probe and the sample surface is the same during detection, thereby enabling the tracking of the sample surface morphology. When measuring hardness, the piezoelectric ceramic needs to drive the probe to sinusoidal vibration.

[0052] However, when the sample stage moves at a high speed (equivalent to a high scanning speed of an atomic force microscope), the travel distance of the piezoelectric ceramic within one cycle is very small. The travel distance of the piezoelectric ceramic for sinusoidal vibration occupies most of its displacement space, which limits the dynamic response capability of the piezoelectric ceramic to changes in the surface undulations of the sample. This means that the atomic force microscope can only measure samples with very small surface undulations. Otherwise, the measurement of the three-dimensional morphology of the sample will not be accurate enough.

[0053] In view of this, the present invention provides a piezoelectric ceramic driving method for high-speed feedback in an AFM system, applied to an atomic force microscope. By controlling the movement depth of the piezoelectric ceramic, the interaction force experienced by the probe is made the same as the preset interaction force. Furthermore, the movement depth change of the hardness-detecting piezoelectric ceramic is controlled to conform to a sinusoidal curve, resulting in a waveform curve of the probe's movement depth change being a superposition of the movement depth changes of the two piezoelectric ceramics. This enables the detection of surface undulations and hardness of the surface under test. The present invention achieves this by separately controlling the movement depth changes of the two piezoelectric ceramics to be independent of each other, ensuring that the movement depth change for detecting the viscosity of the surface under test (i.e., sinusoidal vibration) and the movement depth change for feedback tracking of the surface morphology are two independent movement depth changes. This ensures that the stroke of the sinusoidal vibration does not occupy the stroke of the feedback tracking of the surface morphology. Thus, the atomic force microscope can measure samples with large surface undulations at high scanning speeds.

[0054] To make the above-mentioned objectives, features and beneficial effects of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0055] An embodiment of the present invention is provided below. Figure 1 The present invention provides an atomic force microscope, comprising: a piezoelectric ceramic 100, a probe 200, a deformation detection module 300, and a control module 400;

[0056] The piezoelectric ceramic 100 is connected to the probe 200 and controls the probe 200 to move perpendicular to the first plane 500. The piezoelectric ceramic 100 includes a first deformation force control piezoelectric ceramic 102 and a soft and hardness detection piezoelectric ceramic 101 connected in sequence.

[0057] The deformation detection module 300 is coupled to the input terminal of the control module 400 and is used to detect the deformation of the probe 200 and output a detection signal.

[0058] The control module 400 receives the detection signal at its input terminal and its output terminal is respectively coupled to the control terminal of the first deformation force control piezoelectric ceramic 102 and the control terminal of the soft and hardness detection piezoelectric ceramic 101.

[0059] The control module 400 is configured to: acquire the interaction force received by the probe 200 based on the detection signal, and output a first control signal to the control terminal of the first deformation force control piezoelectric ceramic 102 based on the interaction force, so as to control the change in the movement depth of the piezoelectric ceramic 100, so that the interaction force received by the probe 200 is the same as the preset interaction force; and

[0060] A second control signal is output to the control terminal of the soft and hardness detection piezoelectric ceramic 101, so that the change in the movement depth of the soft and hardness detection piezoelectric ceramic 101 conforms to a sine curve, and the change in the movement depth of the probe 200 is a superimposed waveform curve, which is the superposition of the curve corresponding to the change in the movement depth of the first deformation force control piezoelectric ceramic 102 and the curve corresponding to the change in the movement depth of the soft and hardness detection piezoelectric ceramic 101.

[0061] As can be seen, this invention, by separately controlling the motion depth changes of the two piezoelectric ceramics to be independent of each other, ensures that the motion depth changes for detecting the viscosity of the test surface (i.e., sinusoidal vibration) and the motion depth changes for feedback tracking of the test surface morphology are two independent motion depth changes, guaranteeing the travel distance for feedback tracking of the test surface morphology. This enables atomic force microscopy to measure samples with large surface undulations even at relatively high scanning speeds. Furthermore, this invention controls the motion depth change of the probe to be a superimposed waveform curve of the motion depth changes of the two piezoelectric ceramics, simultaneously achieving the detection of surface undulations and hardness of the test surface.

[0062] As one implementation method, please continue to refer to Figure 1 The preset interaction force includes a preset suspension interaction force and a preset contact interaction force;

[0063] The method for controlling the interaction force on the probe 200 to be the same as the preset interaction force includes:

[0064] The suspended interaction force experienced by the probe 200 is controlled to be the same as the preset suspended interaction force; and

[0065] The contact interaction force experienced by the probe 200 is controlled to be the same as the preset contact interaction force.

[0066] The suspended interaction force is the interaction force experienced by the probe 200 when it is separated from the sample, which is usually 0. However, the present invention is not limited thereto.

[0067] The preset contact interaction force is set by those skilled in the art according to their needs, and is not limited herein.

[0068] As a preferred embodiment, please refer to Figure 2 The preset interaction force has a preset force range, and the piezoelectric ceramic 100 further includes: a second deformation force control piezoelectric ceramic 103;

[0069] The output terminal of the control module 400 is also coupled to the control terminal of the second deformation force control piezoelectric ceramic 103, and the second deformation force control piezoelectric ceramic 103 is connected to the first deformation force control piezoelectric ceramic 102.

[0070] The control module 400 is further configured to: acquire the interaction force received by the probe 200 based on the detection signal; and when the interaction force exceeds the preset force range, output a third control signal to the control terminal of the second deformation force control piezoelectric ceramic 100 based on the interaction force, so as to control the distance between the probe 200 and the first plane 500, so that the interaction force received by the probe 200 is within the preset force range.

[0071] The motion change of the probe 200 is a superimposed curve, which is a superimposed curve of the motion depth change of the first deformation force control piezoelectric ceramic 101, the motion depth change of the softness and hardness detection piezoelectric ceramic 102, and the motion depth change of the second deformation force control piezoelectric ceramic 103.

[0072] Therefore, the present invention also controls the interaction force on the probe 200 within the preset interaction force range when the interaction force on the probe 200 is greater than the preset force range of the preset interaction force (i.e. the undulation of the surface to be measured exceeds the preset range), and coarsely adjusts the distance between the probe 200 and the surface to be measured, so that the atomic force microscope can measure samples with greater undulation of the surface to be measured.

[0073] In practical work, please refer to one implementation method. Figure 3 The atomic force microscope also includes a sample stage 600;

[0074] The sample stage 600 is used to provide the first plane 500, on the surface of the first plane 500, on which the sample 700 is placed. The probe 200 is used to contact the surface of the sample to be tested in order to detect the morphology of the sample 700.

[0075] For one specific implementation method, please refer to Figure 4The probe 200 includes a cantilever beam 201 and a needle tip 202 located at the first end of the cantilever beam 201. The second end of the cantilever beam 201 is coupled to the piezoelectric ceramic 100. The cantilever beam 201 has a first angle with the first plane 500, and the needle tip 202 is perpendicular to the first plane 500.

[0076] In one specific implementation, please refer to Figure 5 The atomic force microscope also includes a probe clip 700 for connecting the second end of the cantilever beam 201 to the piezoelectric ceramic 100.

[0077] In one specific implementation, the deformation detection module 300 includes a laser emitting unit 301 and a position detection unit 302;

[0078] The laser emitting unit 301, the position detection unit 302, and the cantilever beam are all located on the same side of the first plane 500, and the height of the laser emitting unit 301 and the position detection unit 302 from the first plane 500 is greater than the height of the cantilever beam from the first plane 500. The output terminal of the position detection unit 302 is coupled to the input terminal of the control module 400.

[0079] The laser emitting unit 301 is used to emit laser light toward the cantilever beam 201;

[0080] The input terminal of the position detection unit 302 receives the reflected beam of the laser. The position detection unit 302 is used to obtain the deformation of the cantilever beam 201 based on the reflected beam and output the detection signal.

[0081] Among them, such as Figure 4 As shown, the laser emitting unit 301 emits a laser beam to the position detection unit 302, and the position detection unit 302 receives the reflected laser beam. The laser emitting unit is not connected to any other modules.

[0082] In summary, the atomic force microscope of this invention controls the movement depth of the piezoelectric ceramics to ensure that the interaction force experienced by the probe is the same as the preset interaction force, and controls the change in the movement depth of the hardness-detecting piezoelectric ceramics to conform to a sinusoidal curve, so that the change in the probe's movement depth is a superimposed waveform curve of the movement depth changes of the two piezoelectric ceramics. This enables the detection of surface undulations and hardness of the surface under test. Furthermore, by separately controlling the movement depth changes of the two piezoelectric ceramics to be independent of each other, this invention ensures that the movement depth changes for detecting the viscosity of the surface under test (i.e., sinusoidal vibration) and the movement depth changes for feedback tracking of the surface morphology are two independent movement depth changes, guaranteeing the travel distance for feedback tracking of the surface morphology. Thus, the atomic force microscope can measure samples with large surface undulations even at relatively high scanning speeds.

[0083] In addition, please refer to Figure 6 The present invention also provides a piezoelectric ceramic driving method for high-speed feedback in an AFM system, applicable to atomic force microscopy as described above, the method comprising:

[0084] S1: Detects the deformation of the probe and outputs a detection signal;

[0085] S2: Obtain the interaction force on the probe based on the detection signal, and output a first control signal to the control terminal of the first deformation force control piezoelectric ceramic based on the interaction force, so as to control the movement depth of the piezoelectric ceramic, making the interaction force on the probe the same as the preset interaction force; and

[0086] A second control signal is output to the control terminal of the soft and hardness detection piezoelectric ceramic, so that the change in the motion depth of the soft and hardness detection piezoelectric ceramic conforms to a sine curve, and the change in the motion depth of the probe is a superimposed waveform curve, which is the superposition of the curve corresponding to the change in motion depth of the first deformation force control piezoelectric ceramic and the curve corresponding to the change in motion depth of the soft and hardness detection piezoelectric ceramic.

[0087] As a specific implementation method, a method for controlling the interaction force experienced by the probe to be the same as a preset interaction force includes:

[0088] The suspended interaction force experienced by the probe is controlled to be the same as the preset suspended interaction force; and

[0089] The contact interaction force applied to the probe is controlled to be the same as the preset contact interaction force.

[0090] In a preferred embodiment, the method further includes:

[0091] The interaction force on the probe is obtained based on the detection signal. When the interaction force exceeds the preset force range, a third control signal is output to the control terminal of the second deformation force control piezoelectric ceramic based on the interaction force to control the distance between the probe and the first plane, so that the interaction force on the probe is within the preset force range.

[0092] The motion change of the probe is a superimposed curve, which is a superimposed curve of the motion depth change of the first deformation force-controlled piezoelectric ceramic, the motion depth change of the softness and hardness detection piezoelectric ceramic, and the motion depth change of the second deformation force-controlled piezoelectric ceramic.

[0093] Therefore, the present invention also controls the interaction force on the probe within the preset interaction force range when the interaction force on the probe is greater than the preset force range of the preset interaction force (i.e. the undulation of the surface to be measured exceeds the preset range), and coarsely adjusts the distance between the probe and the surface to be measured, so that the atomic force microscope can measure samples with greater undulation of the surface to be measured.

[0094] In summary, the method for measuring the surface properties of the sample in this embodiment of the invention controls the movement depth of the piezoelectric ceramics to ensure that the interaction force experienced by the probe is the same as the preset interaction force, and controls the change in the movement depth of the piezoelectric ceramics for hardness detection to conform to a sinusoidal curve, so that the change in the movement depth of the probe is a superimposed waveform curve of the movement depth changes of the two piezoelectric ceramics. This enables the detection of surface undulations and hardness of the sample surface. By controlling the movement depth changes of the two piezoelectric ceramics to be independent, this invention ensures that the movement depth changes for detecting the viscosity of the sample surface (i.e., sinusoidal vibration) and the movement depth changes for feedback tracking of the surface morphology are two independent movement depth changes, guaranteeing the travel distance for feedback tracking of the surface morphology. This allows the atomic force microscope to measure samples with large surface undulations even at high scanning speeds. Furthermore, this invention coarsely adjusts the distance between the probe and the sample surface by controlling the interaction force experienced by the probe within a preset range when the interaction force exceeds the preset interaction force range (i.e., the undulations of the sample surface exceed the preset range), enabling the atomic force microscope to measure samples with even larger surface undulations.

[0095] While the present invention has been disclosed above, it is not limited thereto. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. An atomic force microscope, characterized in that, include: Probe, piezoelectric ceramic, deformation detection module and control module; The piezoelectric ceramic is connected to the probe and controls the probe to move perpendicular to the first plane. The piezoelectric ceramic includes a first deformation force control piezoelectric ceramic and a softness and hardness detection piezoelectric ceramic connected in sequence. The deformation detection module is coupled to the input terminal of the control module and is used to detect the deformation of the probe and output a detection signal. The control module receives the detection signal at its input terminal and its output terminal is respectively coupled to the control terminal of the first deformation force control piezoelectric ceramic and the control terminal of the soft and hardness detection piezoelectric ceramic. The control module is configured to: acquire the interaction force received by the probe based on the detection signal, and output a first control signal to the control terminal of the first deformation force-controlled piezoelectric ceramic based on the interaction force, so as to control the change in the movement depth of the piezoelectric ceramic, making the interaction force received by the probe the same as the preset interaction force; and A second control signal is output to the control terminal of the soft and hardness detection piezoelectric ceramic, so that the change in the motion depth of the soft and hardness detection piezoelectric ceramic conforms to a sine curve, and the change in the motion depth of the probe is a superimposed waveform curve, which is the superposition of the curve corresponding to the change in motion depth of the first deformation force control piezoelectric ceramic and the curve corresponding to the change in motion depth of the soft and hardness detection piezoelectric ceramic.

2. The atomic force microscope as described in claim 1, characterized in that, The preset interaction force includes a preset suspension interaction force and a preset contact interaction force; The method for controlling the interaction force on the probe to be the same as the preset interaction force includes: The suspended interaction force experienced by the probe is controlled to be the same as the preset suspended interaction force; as well as The contact interaction force applied to the probe is controlled to be the same as the preset contact interaction force.

3. The atomic force microscope as described in claim 2, characterized in that, The preset interaction force has a preset force range, and the piezoelectric ceramic further includes: a second deformation force control piezoelectric ceramic; The output terminal of the control module is coupled to the control terminal of the second deformation force control piezoelectric ceramic, and the second deformation force control piezoelectric ceramic is connected to the first deformation force control piezoelectric ceramic. The control module is further configured to: acquire the interaction force received by the probe based on the detection signal; and when the interaction force exceeds the preset force range, output a third control signal to the control end of the second deformation force control piezoelectric ceramic based on the interaction force, so as to control the distance between the probe and the first plane, so that the interaction force received by the probe is within the preset force range.

4. The atomic force microscope as described in claim 1, characterized in that, The atomic force microscope also includes a sample stage; The sample stage is used to provide the first plane, on the surface of the first plane, on which a sample is placed. The probe is used to contact the surface of the sample to be tested in order to detect the morphology of the sample.

5. The atomic force microscope as described in claim 4, characterized in that, The probe includes a cantilever beam and a needle tip located at a first end of the cantilever beam, a second end of the cantilever beam being coupled to the piezoelectric ceramic, the cantilever beam having a first angle with the first plane, and the needle tip being perpendicular to the first plane.

6. The atomic force microscope as described in claim 5, characterized in that, The atomic force microscope also includes a probe clip for connecting the second end of the cantilever beam to the piezoelectric ceramic.

7. The atomic force microscope as described in claim 5, characterized in that, The deformation detection module includes a laser emitting unit and a position detection unit; The laser emitting unit, the position detection unit, and the cantilever beam are all located on the same side of the first plane, and the height of the laser emitting unit and the position detection unit from the first plane is greater than the height of the cantilever beam from the first plane. The output terminal of the position detection unit is coupled to the input terminal of the control module. The laser emitting unit is used to emit laser light toward the cantilever beam; The input terminal of the position detection unit receives the reflected beam of the laser, and the position detection unit is used to obtain the deformation of the probe based on the reflected beam and output the detection signal.

8. A piezoelectric ceramic driving method for high-speed feedback in an AFM system, applied to the atomic force microscope according to any one of claims 1-7, characterized in that, The method includes: The deformation of the probe is detected, and a detection signal is output. The interaction force experienced by the probe is obtained based on the detection signal, and a first control signal is output to the control end of the first deformation force-controlled piezoelectric ceramic based on the interaction force, so as to control the movement depth of the piezoelectric ceramic, making the interaction force experienced by the probe the same as the preset interaction force; and A second control signal is output to the control terminal of the soft and hardness detection piezoelectric ceramic, so that the change in the motion depth of the soft and hardness detection piezoelectric ceramic conforms to a sine curve, and the change in the motion depth of the probe is a superimposed waveform curve, which is the superposition of the curve corresponding to the change in motion depth of the first deformation force control piezoelectric ceramic and the curve corresponding to the change in motion depth of the soft and hardness detection piezoelectric ceramic.

9. The piezoelectric ceramic driving method for high-speed feedback in an AFM system as described in claim 8, characterized in that, A method for controlling the interaction force acting on the probe to be the same as a preset interaction force includes: The suspended interaction force experienced by the probe is controlled to be the same as the preset suspended interaction force; and The contact interaction force applied to the probe is controlled to be the same as the preset contact interaction force.

10. The piezoelectric ceramic driving method for high-speed feedback in an AFM system as described in claim 9, characterized in that, The method further includes: The interaction force on the probe is obtained based on the detection signal. When the interaction force exceeds the preset force range, a third control signal is output to the control terminal of the second deformation force control piezoelectric ceramic based on the interaction force to control the distance between the probe and the first plane, so that the interaction force on the probe is within the preset force range.

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