CN115480077A - Atomic force microscope control method with cooperative work of non-contact mode and contact mode - Google Patents

Abstract

The atomic force microscope control method in which the non-contact mode and the contact mode work together solves the problem that the existing combination of the two working modes cannot be characterized in situ, and belongs to the atomic force microscope technology. The cantilever beam of the atomic force microscope of the present invention drives the probe above the sample, and the method includes: S1. The cantilever beam of the atomic force microscope drives the probe at a set distance above the sample, excites the sensor to excite the cantilever beam to drive the probe to resonate, and tests the long-range performance; S2. The excitation sensor stops excitation, drives the sample to move upward or the probe moves downward so that the surface of the sample is close to the probe above, and the excitation sensor generates an excitation signal to act on the sample and/or probe to test the physical and chemical properties of the sample; S3 1. The excitation sensor stops generating the excitation signal, and at the same time, the sample or probe returns to its original position, and the sample or probe is driven to move so that the cantilever beam of the atomic force microscope drives the probe to move to the next test position point, and then enters S1.

Description

Control method of atomic force microscope with non-contact mode and contact mode working together

technical field

The invention relates to an atomic force microscope control method in which a non-contact mode and a contact mode work together, and belongs to the atomic force microscope technology.

Background technique

Atomic force microscope is an important equipment for nanoscale material surface characterization, which is widely used in materials, chemistry, biology, medicine, semiconductor and other fields. Atomic force microscopes are mainly divided into contact mode and non-contact mode according to their working modes. Among them, the contact mode is the most typical static mode. During the scanning process, the probe is close to the surface of the sample, and the attractive or repulsive force acts directly on the cantilever beam, thereby realizing the measurement of the physical and chemical properties of the surface. According to the different types of physical signals used, the non-contact mode can be divided into amplitude modulation mode, frequency modulation mode, force modulation mode, higher harmonic modulation mode and dissipative signal mode, etc.

The contact mode is the easiest way for the atomic force microscope to obtain the surface topography of the sample. The Z-axis scanner ensures that the deflection of the cantilever on the sample surface is always constant, and the topography signal is also generated according to its position signal. Power microscopy and stress-strain testing techniques have become indispensable and important characterization techniques in the field of scanning probe microscopy.

In the non-contact mode, the tip of the probe is never in contact with the surface of the sample. The probe resonates within a certain distance from the sample surface. The physical signal of the sensor resonance corresponds to the distance between the sample and the probe. The parameters are brought into a specific physical model to obtain the corresponding Physical properties, this method can protect the sample surface from the damage of the probe to the greatest extent, and at the same time has a very high shape resolution.

The atomic force microscope has been able to achieve excellent performance characterization in any single working mode of contact mode or non-contact mode, but how to effectively combine the two working modes still faces many challenges. Corresponding physical properties of all test positions on the sample surface. After the probe returns to the initial test position, it is then in contact with the sample. The contact mode test is carried out in the order of each test position in the non-contact mode, and other physical properties of the sample are obtained. Performance, to complete the test of the surface characteristics of the sample; for the same test position point, two modes of scanning will cause drift, and the second scan or the intervention of various external devices cannot determine the multi-field of a fixed test position point in space Performance Characterization. Therefore, the combination of the two existing working modes inevitably leads to in-situ characterization due to mechanical operation and other reasons in space, and also causes the problem that the characterization of various physical and chemical properties is not instant in time, so that it cannot be objective reflect the real relationship between the interactions between the various physical fields at the same time.

Contents of the invention

Aiming at the problem that the existing combination of the two working modes cannot be characterized in situ and cannot objectively reflect the real relationship between the interactions between the physical fields at the same time, the present invention provides a cooperative working mode of the non-contact mode and the contact mode. Atomic Force Microscopy Control Methods.

A control method of an atomic force microscope in which a non-contact mode and a contact mode work together in the present invention, the cantilever beam of the atomic force microscope drives the probe above the sample, and the method includes:

S1. The cantilever beam of the atomic force microscope drives the probe at a set distance above the sample, and the sensor excites the cantilever beam to drive the probe to resonate to test long-range performance; it can also switch from one non-contact mode to another non-contact mode, so that Another non-contact mode sensor excitation to test long-range performance.

S2. The excitation sensor stops excitation, drives the sample to move upward or the probe moves downward so that the surface of the sample is close to the probe above, and the excitation sensor generates an excitation signal to act on the sample and/or the probe to test the physical and chemical properties of the sample; It is possible to switch from one contact mode to another, so that the excitation sensor of the other contact mode generates an excitation signal to test the physicochemical properties of the sample.

S3. The excitation sensor stops generating the excitation signal, and at the same time, the sample or probe returns to the original position, and the sample or probe is driven to move so that the cantilever beam of the atomic force microscope drives the probe to move to the next test position point, and turns to S1.

The present invention can also be in the contact mode first, and then the non-contact mode, specifically including:

S1. The cantilever beam of the atomic force microscope drives the probe at a set distance above the sample, drives the sample to move upward or the probe moves downward so that the surface of the sample is close to the probe above, and the excitation sensor generates an excitation signal to act on the sample and/or The probe can test the physical and chemical properties of the sample; it can also switch from one contact mode to another, so that the excitation sensor of the other contact mode can generate an excitation signal to test the physical and chemical properties of the sample.

S2. The excitation sensor stops generating the excitation signal, and at the same time the sample or probe returns to its original position, the excitation sensor excites the cantilever beam to drive the probe to resonate, and tests the long-range performance; it can also switch from one non-contact mode to another non-contact mode, Enable another non-contact mode sensor excitation to image the sample surface.

S3. The excitation sensor stops excitation, drives the sample or the probe to move so that the cantilever beam of the atomic force microscope drives the probe to move to the next test position, and turns to S1.

Preferably, the physical and chemical properties include the morphology, mechanical properties, thermal properties, electrical properties, optical properties, magnetic properties, piezoelectric properties, and electrochemical properties of the sample.

Preferably, the excitation signal includes electrical signal, magnetic signal, thermal signal, optical signal and mechanical signal.

Preferably, the long-range performance test includes: imaging of sample morphology, magnetic field force imaging and electrostatic force imaging.

The beneficial effect of the present invention is that the present invention adopts the method of in-situ fast switching, and adjusts the vertical distance between the probe and the sample at the same point to realize the in-situ measurement of short-range and long-range performance in turn, so that the atomic force microscope can be used in non- Use contact mode to measure physicochemical properties of a sample while scanning in contact mode. The present invention has real-time characterization of various physical and chemical properties, and the obtained test performance can objectively reflect the true relationship of interaction between various physical fields at the same time. The invention can solve the problem of incompatibility between the non-contact mode and the contact mode of the atomic force microscope.

Description of drawings

Fig. 1 is a schematic diagram of the signal timing of the time-sharing excitation control system;

2 is a schematic diagram of the hardware structure of the atomic force microscope in the first embodiment of the present invention when testing performance. In the figure, 1 represents the position of the probe in the non-contact mode, 2 represents the position of the probe in the contact mode; 3 represents the sample; 4 Indicates piezoelectric scanning tube;

FIG. 3 is a real-time signal for switching between non-contact mode-contact mode-non-contact mode in Embodiment 1. FIG. Among them, signal 1 is the real-time position signal of the cantilever beam driven by the time-sharing excitation control system, and signal 2 is the current signal of contact conduction between the probe and the sample;

Fig. 4 is the stress-strain relationship figure between probe and sample in embodiment 2;

Fig. 5 is the topography figure of embodiment 3 atomic force microscope scanning HOPG sample;

FIG. 6 is the current diagram of the HOPG sample scanned by the atomic force microscope in Example 3.

detailed description

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

It should be noted that, in the case of no conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, but not as a limitation of the present invention.

The method for controlling the atomic force microscope in which the non-contact mode and the contact mode work together in the present application, the cantilever beam of the atomic force microscope drives the probe above the sample, including:

Step 1. The cantilever beam of the atomic force microscope drives the probe at a set distance above the sample, and the sensor excites the cantilever beam to drive the probe to resonate to test the long-range performance;

Step 2. Exciting the sensor to stop the excitation, driving the sample to move upward or the probe to move downward so that the surface of the sample is close to the probe above, and the sensor is excited to generate an excitation signal to act on the sample and/or the probe to test the physical and chemical properties of the sample;

Step 3. The excitation sensor stops generating the excitation signal, and at the same time, the sample or probe returns to its original position, and the sample or probe is driven to move so that the cantilever beam of the atomic force microscope drives the probe to move to the next test position point, and then turn to step 1.

In this application, when testing the same test position point, the time-sharing excitation control method is used to first perform the non-contact mode test, then the contact mode test, and then move to the next test position point to perform the non-contact mode test. Adjusting the vertical distance between the probe and the sample sequentially realizes the in-situ measurement of long-range and short-range properties, enabling the AFM to measure the physicochemical properties of the sample using the contact mode while scanning in the non-contact mode. Since this embodiment collects and characterizes the parameters of non-contact mode and contact mode at a certain test position point, it can ensure that the force, heat, electricity, light, magnetism, etc. of the sample itself at the same test position point can be truly characterized. Performance, this implementation mode can realize the combined application of the two scanning technologies of the non-contact mode and the contact mode, thereby solving the problem of incompatibility between the non-contact mode and the contact mode.

In this application, it is also possible to use the time-sharing excitation control method when testing the same test position point to first perform the contact mode test, then the non-contact mode test, and then move to the next test position point to perform the contact mode test. On-point adjustment of the vertical distance between the probe and the sample sequentially enables in situ measurement of process and remote performance, enabling the AFM to measure the physicochemical properties of the sample using a non-contact mode while scanning in a contact mode.

The switching of the operation mode in this application includes switching from non-contact mode to contact mode, switching from contact mode to non-contact mode, and also including switching from non-contact mode to another non-contact mode or switching from contact mode to another contact mode. model. The combined application of the two scanning technologies of the non-contact mode and the contact mode is any permutation and combination of any number of non-contact modes and any number of contact modes. For example, non-contact mode-contact mode-contact mode-non-contact mode-contact mode, or contact mode-contact mode-non-contact mode-non-contact mode-contact mode, and so on. After assigning specific functions to the operating mode of the atomic force microscope, give an example of the specific switching scheme: imaging mode (non-contact mode)-conductive force mode (contact mode)-electrostatic force mode (non-contact mode)-imaging mode (non-contact mode) .

The physical and chemical properties in this application include the morphology, mechanical properties, thermal properties, electrical properties, optical properties, magnetic properties, piezoelectric properties, and electrochemical properties of the sample.

In this application, excitation signals include electrical signals, magnetic signals, thermal signals, optical signals and mechanical signals.

The test of long-range performance in this application includes: imaging of sample morphology, magnetic field force imaging and electrostatic force imaging.

Specific implementation mode one:

The hardware structure of this embodiment is shown in Figure 2. The cantilever beam of the atomic force microscope drives the probe above the sample 3, and the sample 3 is placed on the piezoelectric scanning tube 4; the hardware structure of this embodiment also includes exciting the cantilever beam to drive the probe. Resonant excitation sensor, position sensor that drives the piezoelectric scanning tube to move upward, excitation sensor in contact mode, excitation sensor in non-contact mode, sensor that drives horizontal movement of the piezoelectric scanning tube;

The specific control process includes: first, the parameters to be set are transmitted to the time-sharing excitation control system through the host computer, and the time-sharing excitation control system is loaded into the corresponding sensor through corresponding signal generation and digital-to-analog conversion. At the same time, the hardware structure transmits the feedback signal back to the time-sharing excitation control system through the analog-to-digital conversion module during work, and then realizes the time-sharing cooperative excitation technology of non-contact mode and contact mode under the action of control methods such as phase-locked loop and negative feedback. .

When the working mode is set to non-contact mode-contact mode-non-contact mode, when the excitation signal sent by the time-sharing excitation control system through each sensor acts on the hardware structure after digital-to-analog conversion, take Figure 2 as an example, when the atomic force microscope is in In the non-contact mode state, the cantilever beam drives the probe to keep a certain distance from the sample at position 1 and the sample 3, and the sensor is excited to excite the cantilever beam to resonate, and cooperate with the negative feedback loop to keep the probe and the sample in a non-contact state. The feedback parameter signal can be characterized according to the specific needs The physical and chemical properties of the sample are set to various physical parameters such as frequency, amplitude, phase, and current. The amplitude modulation mode atomic force microscope realizes the imaging of the sample surface, and uses the non-contact mode to characterize the long-range performance of the sample, such as: sample morphology imaging, magnetic field force Imaging and electrostatic force imaging; after completing the operation steps of the above non-contact mode, when the atomic force microscope switches to the contact mode, the piezoelectric scanning tube 4 is displaced by the driving signal of the position signal sensor to move the sample upwards, so that the cantilever beam drives the probe The position 2 is in contact with the sample 3, so that the excitation sensor can characterize the corresponding contact mode of the sample 3. At this time, the negative feedback loop with the amplitude as the setting parameter is closed;

Finally, after performing the test task in the contact mode, when the atomic force microscope switches to the non-contact mode, the piezoelectric scanning tube 4 will produce a reverse displacement, move the sample 3 downward, and return to the original position, so that the cantilever beam returns to position 1 Keep away from the sample 3 to maintain the non-contact mode operation, at this time the negative feedback loop will be re-opened to maintain the dynamic non-contact state between the probe and the sample.

In the mode of operation described above, it is assumed that an additional determined property is characterized as a conductive property. When the clock signal reaches the switching time set by the time-sharing excitation control system, the excitation signal used to drive the cantilever beam to resonate in the non-contact mode is immediately turned off. At this time, the system drives the piezoelectric scanning tube forward to make the probe contact with the sample. A clear current signal can be seen. After the current signal is tested, the atomic force microscope switches to the non-contact mode, the probe leaves the sample surface so that the current disappears, and the excitation signal of the excitation sensor resumes to excite the cantilever to maintain the resonance state. At two mode switching points, the changes of the excitation signal and the current signal can be clearly corresponded.

The signal timing diagram of the time-sharing excitation control system is shown in Figure 1. The atomic force microscope operates in a non-contact mode before time t ₀ , and the excitation signal of the excitation sensor is turned off at time t _0. At the same time, the position sensor sends a driving signal to the piezoelectric scanning tube 4 Drive the sample to move upwards, so that the probe and the sample are in a contact state, and use the excitation sensor to apply an additional excitation signal to the probe and/or sample to start the detection of specific parameters. After completing the relevant detection instructions of the contact mode, at time t ₁ Turn on the excitation signal of the excitation sensor again, and at the same time adjust the drive signal of the position sensor to the piezoelectric scanning tube 4, and the piezoelectric scanning tube 4 drives the sample to move downward, so that the surface of the sample returns to its original position, and close the excitation signal of the excitation sensor in the contact mode . That is, the atomic force microscope completes the switching from the non-contact mode to the contact mode at time t ₀ , maintains the contact state during the period from t ₀ to t ₁ , and then returns to the non-contact mode at time t ₁ .

Specific embodiment two: The difference between the hardware structure of this embodiment and that shown in Figure 2 is that the sample is fixed, the cantilever beam of the atomic force microscope drives the probe above the sample 3, the piezoelectric scanning tube and the cantilever beam are fixed, and the piezoelectric scanning tube is driven , so that the cantilever beam drives the probe to move vertically and horizontally above the sample 3 . The sensors in the hardware structure include the excitation sensor that excites the cantilever beam to drive the probe to resonate, the position sensor that drives the piezoelectric scanning tube to move downward, the excitation sensor in the contact mode, the excitation sensor in the non-contact mode, and the horizontal plane of the piezoelectric scanning tube. moving sensors;

The specific process includes: first, the parameters to be set are transmitted to the time-sharing excitation control system through the host computer, and the time-sharing excitation control system is loaded into the corresponding sensor through corresponding signal generation and digital-to-analog conversion. At the same time, the hardware structure transmits the feedback signal back to the time-sharing excitation control system through the analog-to-digital conversion module during work, and then realizes the time-sharing cooperative excitation technology of non-contact mode and contact mode under the action of control methods such as phase-locked loop and negative feedback. .

When the working mode is set to non-contact mode-contact mode-non-contact mode, the excitation signal sent by the time-sharing excitation control system through each sensor acts on the hardware structure after digital-to-analog conversion. When the atomic force microscope is in the state of non-contact mode, the cantilever The beam drives the probe to keep a certain distance from the sample, the sensor is excited to excite the cantilever beam to resonate, and the negative feedback loop is used to keep the probe and the sample in a non-contact state. The feedback parameter signal can be set to frequency, amplitude, Various physical parameters such as phase and current, the amplitude modulation mode atomic force microscope realizes the imaging of the sample surface, and uses the non-contact mode to characterize the long-range performance of the sample, such as: sample morphology imaging, magnetic field force imaging and electrostatic force imaging; when the above non-contact After the operation steps of the AFM mode, when the atomic force microscope is switched to the contact mode, the piezoelectric scanning tube is displaced by the driving signal of the position signal sensor, so that the cantilever beam drives the probe to move downward, so that the probe is in contact with the sample, so that the excitation sensor can Perform corresponding contact mode characterization on the sample, at this time, the negative feedback loop with the amplitude as the setting parameter is closed;

Finally, when the atomic force microscope is switched to the non-contact mode after performing the test task in the contact mode, the piezoelectric scanning tube 4 will produce a reverse displacement, so that the cantilever beam returns to position 1 away from the sample 3 and returns to its original position, thereby maintaining non-contact Mode operation, at this time the negative feedback loop will be re-opened to maintain the dynamic non-contact state between the probe and the sample.

The signal sequence of the time-sharing excitation control system is the same as that in Figure 1. The atomic force microscope operates in non-contact mode before time _t0 , and the excitation signal of the excitation sensor is turned off at time _t0 . At the same time, the position sensor sends a driving signal to the piezoelectric scanning tube 4 to make the probe The needle moves downward and is in contact with the sample, and the excitation sensor is used to apply an additional excitation signal to the probe and/or sample to start the detection of specific parameters. After completing the relevant detection instructions of the contact mode, the excitation is restarted at time t ₁ The sensor excitation signal is adjusted, and the driving signal of the position sensor is adjusted at the same time to make the probe leave the sample surface and return to its original position, and the excitation signal of the excitation sensor in the contact mode is turned off. That is, the atomic force microscope completes the switching from the non-contact mode to the contact mode at time t ₀ , maintains the contact state during the period from t ₀ to t ₁ , and then returns to the non-contact mode at time t ₁ . Provide specific embodiment below:

Example 1:

The atomic force microscope implements a design scheme of non-contact mode-contact mode-non-contact mode switching at a test position on the HOPG sample. Characterize the morphology of the sample in non-contact mode and characterize the conductivity of the sample in contact mode.

As shown in Figure 3, signal 1 is the real-time position signal of the cantilever beam when the time-sharing excitation control system controls the position sensor to send the driving signal, and signal 2 is the current signal of the contact conduction between the probe and the sample.

The front end of signal 1 corresponds to the vibration signal of the cantilever beam maintaining the resonance state in the non-contact mode. At t=0, the piezoelectric scanning tube drives the cantilever beam to press down on the sample surface. At this time, the amplitude of signal 1 is greatly reduced, that is, in the contact mode Resonance actively excited by the lower probe stops. In addition, the horizontal position of signal 1 shifts upwards and the voltage increases, reflecting the change of the Z-axis position of the piezoelectric scanning tube. At time t=0, an obvious contact current is generated between the probe and the sample, and the signal strength is 40 millivolts.

After collecting the contact current between the probe and the sample for about 3 milliseconds, the system executes the switching command from the contact mode to the non-contact mode. At this time, the initial position of the Z-axis voltage drop of the piezoelectric scanning tube keeps the probe away from the surface of the HOPG sample, and the excitation signal of the excitation sensor restarts to maintain the resonance state of the cantilever beam. At the same time, the contact current signal disappears.

So far, the command to measure the contact current by switching between the non-contact mode-contact mode-non-contact mode at a test location is completed, and it takes about 4 milliseconds.

Example 2:

The atomic force microscope implements a design scheme of non-contact mode-contact mode-non-contact mode switching at a test position on the HOPG sample. Characterize the morphology of the sample in the non-contact mode, and characterize the stress-strain performance of the sample in the contact mode.

The switching steps of non-contact mode-contact mode-non-contact mode are basically the same as the above-mentioned embodiment 1, the difference is that when switching to contact mode, the opened performance characterization function is the stress-strain test.

As shown in Figure 4, the curve composed of square data points is the contact stress curve when the probe and the sample are switched from the non-contact state to the contact state, and the curve composed of circular data points is the switch from the contact state to the non-contact state between the probe and the sample. desorption stress curve. According to international practice, the contact stress curve is symmetrically processed about the Y-axis at the zero point in the figure, which is convenient for observing and comparing two stress-strain curves in the figure at the same time.

After the system switches to the contact mode, the piezoelectric scanning tube pushes the sample and the probe closer together. From the contact stress curve in Figure 4, it can be seen that when the distance between the sample and the probe moves within 3 nanometers, there will be a maximum attraction force of about 8 Newtons between the two, and the repulsive force will start when the distance between the sample and the probe is less than 2.5 nanometers. The repulsive force and attractive force between the probe and the sample reach a balance state when the spacing is 2 nm. Thereafter, as the probe approaches the sample, a maximum repulsive force of about 50 Newtons can be generated between the two.

When the system switches to non-contact mode, the piezo scan tube moves the sample away from the probe. At this time, the repulsive force between the probe and the sample gradually decreases. Observing the desorption stress curve shows that since the probe is pressed into the sample, a maximum attractive force of 18 Newtons will be generated during desorption, which is significantly greater than the maximum force during contact. attraction. In addition, the equilibrium point of the gravitational-repulsive force and the starting point of the gravitational force between the sample and the probe in the desorption stage moved backward by about 2 nanometers and 7 nanometers, respectively.

Example 3:

The atomic force microscope implements a non-contact mode-contact mode-non-contact mode switching design scheme on a 1 micron by 1 micron area on the HOPG sample. Characterize the morphology of the sample in non-contact mode and characterize the conductivity of the sample in contact mode.

This embodiment is a set after performing the single test position point operation in Embodiment 1 on the X-axis 512 by the Y-axis 512 points in the scanning area, and the control command on each test position point is the same as that in the embodiment 1 with the same command. In addition, it is necessary to additionally set the basic parameters of the scanning probe microscope, that is, the scanning position, the number of scanning points, the scanning speed, the scanning slope and so on.

Fig. 5 is a topography diagram of a specific region of the HOPG sample scanned by an atomic force microscope, and Fig. 6 is a contact current diagram of the same region of the HOPG sample scanned by an atomic force microscope. Comparing the two images, it can be seen that there is an accurate correspondence between the topography image of the sample and the contact current image, and the high and low fluctuations of the topography correspond to the magnitude of the contact current between the sample and the probe, and there is also a change in size that conforms to the topography rule.

It can be proved that the non-contact mode and contact mode cooperative working technology of the present application can indeed realize the multi-field coupling in-situ characterization of materials, and solve the inability of the topography map and current map caused by the intrinsic defects of mechanical equipment in the traditional secondary scanning technology. exact problem.

Although the invention is described herein with reference to specific embodiments, it should be understood that these embodiments are merely illustrative of the principles and applications of the invention. It is therefore to be understood that numerous modifications may be made to the exemplary embodiments and that other arrangements may be devised without departing from the spirit and scope of the invention as defined by the appended claims. It shall be understood that different dependent claims and features described herein may be combined in a different way than that described in the original claims. It will also be appreciated that features described in connection with individual embodiments can be used in other described embodiments.

Claims (10)

1. The atomic force microscope control method with cooperative work of a non-contact mode and a contact mode is characterized in that a cantilever beam of the atomic force microscope drives a probe to be above a sample, and the method comprises the following steps:

s1, a cantilever beam of an atomic force microscope drives a probe to be arranged at a set distance above a sample, a sensor is excited to excite the cantilever beam to drive the probe to resonate, and long-range performance is tested;

s2, stopping excitation of the excitation sensor, driving the sample to move upwards or the probe to move downwards so as to enable the surface of the sample to be tightly attached to the probe above, and enabling the excitation sensor to generate an excitation signal to act on the sample and/or the probe so as to test the physical and chemical characteristics of the sample;

and S3, stopping generating an excitation signal by the excitation sensor, returning the sample or the probe to the original position, driving the sample or the probe to move, driving the probe to move to a next test position point by a cantilever beam of the atomic force microscope, and switching to S1.

2. The method as claimed in claim 1, wherein the step S1 further comprises switching from one non-contact mode to another non-contact mode, so as to excite another non-contact mode sensor and test long-range performance.

3. The method for controlling an atomic force microscope according to the non-contact mode and the contact mode in cooperation, wherein the step S2 further comprises switching from one contact mode to another contact mode, so that an excitation signal is generated by an excitation sensor of the other contact mode, and the physicochemical characteristic of the sample is tested.

4. The atomic force microscope control method of the cooperative work of the non-contact mode and the contact mode is characterized in that a cantilever beam of the atomic force microscope drives a probe to be above a sample, and the method comprises the following steps:

s1, a cantilever beam of an atomic force microscope drives a probe to move upwards or downwards at a set distance above a sample, so that the surface of the sample is attached to the probe above the sample, an excitation sensor generates an excitation signal to act on the sample and/or the probe, and the physical and chemical characteristics of the sample are tested;

s2, the excitation sensor stops generating an excitation signal, and meanwhile, the sample or the probe returns to the original position, the excitation sensor excites the cantilever beam to drive the probe to resonate, and long-range performance is tested;

and S3, exciting the sensor to stop exciting, driving the sample or the probe to move, driving the cantilever beam of the atomic force microscope to drive the probe to move to the next test position point, and switching to S1.

5. The method as claimed in claim 4, wherein the step S1 further comprises switching from one contact mode to another contact mode, so that the excitation sensor of the other contact mode generates the excitation signal to test the physicochemical characteristic of the sample.

6. The method for controlling an atomic force microscope according to the cooperative working of the non-contact mode and the contact mode of the claim 4 or 5, wherein the step S2 further comprises switching from one non-contact mode to another non-contact mode, so that the sensor in the other non-contact mode is excited to image the surface of the sample.

7. The method for controlling an atomic force microscope according to the claims 1 or 4, wherein in the steps S2 and S3, a piezoelectric ceramic device is used to drive the sample or the probe to move.

8. The method for controlling an atomic force microscope according to claim 1 or 4, wherein the physical and chemical properties include morphology, mechanical properties, thermal properties, electrical properties, optical properties, magnetic properties, piezoelectric properties, and electrochemical properties of the sample.

9. The method for controlling an atomic force microscope according to claim 1 or 4, wherein the excitation signal includes an electrical signal, a magnetic signal, a thermal signal, an optical signal and a mechanical signal.

10. The method for controlling an atomic force microscope according to claim 1 or 4, wherein the testing the long-range performance comprises: and (3) imaging the appearance of the sample, imaging the magnetic field force and imaging the electrostatic force.

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