Submerged atomic force microscope measuring head and atomic force microscope using method
By designing an adjustment device in the atomic force microscope probe to control the liquid level position, the problem of difficult to determine the resonance frequency of the probe cantilever in a liquid environment is solved, and the imaging quality and detection efficiency are improved.
Patent Information
- Application Number
- CN202411636197.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-15
- Publication Date
- 2025-03-07
AI Technical Summary
When using atomic force microscope (AFM) to image biomaterials in liquid environments, the probe cantilever is in the liquid environment, making it difficult to determine the resonance frequency and affecting the imaging quality.
A sub-liquid atomic force microscope probe is designed, including a cantilever beam probe, a piezoelectric actuator, an isolation cavity and an adjustment device. The amount and volume of the gas in the isolation chamber are adjusted by the adjustment device, and the liquid level position is controlled, so that the needle tip of the cantilever beam probe vibrates in the liquid environment, while the cantilever is maintained in the gas environment.
It effectively avoids interference from the liquid environment on AFM, improves the resonance frequency recognition accuracy of the probe cantilever, and improves the detection effect of AFM on the object to be measured in the liquid.
Smart Images
Figure CN119574915A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of scanning probe microscopes, and in particular relates to a submerged atomic force microscope probe and an atomic force microscope use method. Background Art
[0002] Atomic force microscopy (AFM) is a high-resolution scanning probe microscopy technology that uses the interaction force between the detection probe and the sample surface to scan the sample surface to obtain information such as the sample surface morphology and physical properties. It is widely used in fields such as materials science, biology, and physics.
[0003] When using AFM to image biological materials, in order to maintain the physiological activity or inherent properties of the sample, the object to be measured needs to be placed in a liquid environment and observed using AFM, for example, using AFM to detect DNA, living cells, and proteins. When imaging biological materials, since the object to be measured is usually soft and easily damaged, tapping mode AFM is usually used to reduce the impact or damage to the object to be measured. In tapping mode, the AFM's probe cantilever oscillates at a certain frequency, and only contacts the sample surface or generates interaction force with the sample surface for part of the time during the oscillation. By measuring changes in amplitude, phase, or resonant frequency, information such as the sample's surface morphology and physical properties can be obtained.
[0004] In order to detect samples in a liquid environment, the AFM probe cantilever needs to be placed in the liquid environment where the sample is located. However, when the probe cantilever is in a liquid environment, multiple peaks will appear, making it difficult to determine the resonant frequency of the probe cantilever, which will interfere with the imaging quality of the AFM and cause difficulties in AFM imaging.
[0005] The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known to a person of ordinary skill in the art. Summary of the invention
[0006] In view of the technical problem that the existing AFM is difficult to use and image when detecting samples in a liquid environment due to the influence of the liquid environment, the present invention first provides an underwater atomic force microscope probe, including a cantilever probe, a piezoelectric actuator, an isolation cavity, and an adjustment device, wherein the isolation cavity is a hollow cavity opening along a first plane, the cantilever probe arranged in the isolation cavity extends toward the opening and its needle tip does not protrude from the opening, the cantilever probe vibrates under the action of the piezoelectric actuator, and the adjustment device is constructed in a form capable of adjusting at least one of the amount of gas in the isolation cavity and the volume of the isolation cavity.
[0007] According to a specific embodiment of the present invention, the isolation cavity is provided with a light-transmitting window, and the light-transmitting window is constructed to allow light passing through the light-transmitting window to irradiate the cantilever beam probe, and / or allow the light beam reflected by the cantilever beam probe to be emitted outside the isolation cavity through the light-transmitting window.
[0008] According to a specific embodiment of the present invention, the regulating device includes a ventilation switch, one end of which is connected to the inner side of the isolation chamber, and the other end of which is connected to the external gas environment or gas source of the isolation chamber.
[0009] According to a specific embodiment of the present invention, the regulating device includes a volume adjusting device, and the volume adjusting device is configured to at least be able to change the form of the cavity wall of the isolation cavity.
[0010] Another aspect of the present application provides a method for using an atomic force microscope, using the aforementioned submersible atomic force microscope probe, comprising the following steps: S1: Fill the isolation chamber with gas and allow the opening of the isolation chamber to enter the liquid surface downward; S2: adjusting the liquid level position in the isolation chamber by the adjusting device so that the cantilever beam probe is in a state where the needle tip enters the liquid surface and the cantilever does not enter the liquid surface; S3: Use the cantilever beam probe to detect the object under test.
[0011] According to a specific embodiment of the present invention, in S2, the cantilever beam probe is placed in a state where the tip of the cantilever beam enters the liquid surface and the cantilever beam does not enter the liquid surface by the following method: A201: separating the tip of the cantilever beam probe from the liquid surface; driving the tip of the cantilever beam probe to vibrate by the piezoelectric actuator; A202: adjusting at least one of the amount of gas in the isolation chamber and the volume of the isolation chamber by the adjustment device so that the liquid level in the isolation chamber gradually rises, and detecting the force applied to the needle tip at the same time; A203: When the force on the tip of the cantilever beam probe changes suddenly for the first time, stop the adjusting device.
[0012] According to a specific embodiment of the present invention, S3 further includes: A301: driving the tip of the cantilever beam probe to vibrate by the piezoelectric actuator; A302: moving the underwater atomic force microscope probe, and stopping moving the underwater atomic force microscope probe when the interaction force between the tip of the cantilever beam probe and the object to be measured reaches a preset condition; A303: Use a cantilever beam probe to detect the object under test.
[0013] According to a specific embodiment of the present invention, when the opening of the isolation chamber is below the liquid surface, the first plane is parallel to the liquid surface.
[0014] According to a specific embodiment of the present invention, in A303, the cantilever beam probe is moved along a preset direction to scan the object to be measured so as to detect the object to be measured.
[0015] According to a specific embodiment of the present invention, the underwater atomic force microscope probe is moved along a preset direction, thereby moving the cantilever beam probe along the preset direction.
[0016] The underwater atomic force microscope probe provided by the present invention has at least the following beneficial effects: by using an adjustment device to adjust the position of the liquid surface, it is possible to prevent the cantilever of the cantilever probe from entering the liquid environment and causing interference with the detection; on the other hand, it is possible to keep the tip of the cantilever probe in the liquid environment during vibration, so as to prevent the tip of the cantilever probe from repeatedly entering and exiting the liquid environment, causing changes in its force and causing interference with the detection, and it is easy to use.
[0017] The method for using the atomic force microscope provided by the present invention has at least the following beneficial effects: by using an atomic force microscope with an underwater atomic force microscope probe, it is possible to effectively solve the problems of difficulty in determining the resonance frequency of the probe cantilever, low imaging quality, and difficulty in imaging when the probe cantilever is in a liquid environment, thereby greatly improving the AFM detection effect on the object being measured in the liquid. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Figure 1 The figure is a schematic diagram of the overall structure of an embodiment of an underwater atomic force microscope probe.
[0019] Figure 2 for Figure 1 The figure shows a schematic diagram of an underwater atomic force microscope probe in use.
[0020] Figure 3 for Figure 1 Schematic diagram of another usage state of the underwater atomic force microscope probe shown.
[0021] Figure 4 It is a schematic diagram of the overall structure of another embodiment of the underwater atomic force microscope probe.
[0022] Figure 5 A schematic diagram of a usage state of the volume adjustment device.
[0023] Figure 6 A schematic diagram of another usage state of the volume adjustment device. DETAILED DESCRIPTION
[0024] When testing samples in a liquid environment, existing AFMs are difficult to use and difficult to image due to the influence of the liquid environment. In view of this, the present application provides a submerged atomic force microscope probe and an atomic force microscope using the submerged atomic force microscope probe, which can avoid the interference of the liquid environment on the use of AFM, can quickly and conveniently detect the object to be tested in the liquid, and is particularly suitable for the detection of biological samples.
[0025] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. It should be noted that the drawings are all in a very simplified form and use inaccurate ratios, which are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention.
[0026] The present invention first provides an underwater atomic force microscope probe, including a cantilever probe 100, a piezoelectric actuator 200, an isolation cavity 300, and an adjustment device 400. The isolation cavity 300 is a hollow cavity C opened along a first plane S1. The cantilever probe 100 arranged in the isolation cavity 300 extends toward the opening 301 and its needle tip 110 does not protrude from the opening. The cantilever probe 100 vibrates under the action of the piezoelectric actuator 200. The adjustment device 400 is constructed in a form capable of adjusting at least one of the amount of gas in the isolation cavity 300 and the volume of the isolation cavity 300.
[0027] See also Figure 1 , shows a feasible implementation, wherein the cantilever 120 of the cantilever beam probe 100 is connected to the piezoelectric actuator 200, the piezoelectric actuator 200 is mounted on the bracket 310 inside the isolation cavity 300, and the isolation cavity 300 surrounds the piezoelectric actuator 200 and the cantilever beam probe 100 inside its cavity C. The cantilever beam probe 100 is inclined toward the opening 301 of the isolation cavity 300 in the length direction thereof, so that the needle tip 100 extends toward the opening 301 of the isolation cavity 300, so as to contact the object to be measured near the opening 301 of the isolation cavity 300.
[0028] When using the underwater atomic force microscope probe provided by the present invention, the isolation cavity 300 can be placed in the liquid 500 from the air environment, so that the liquid 500 closes the opening 301 of the isolation cavity 300. At this time, the inner side of the isolation cavity 300 can accommodate part of the gas. Under the action of the gas, the liquid 500 can be prevented from entering the interior of the isolation cavity 300, thereby preventing the liquid 500 from submerging the cantilever beam probe 100 inside the isolation cavity 300.
[0029] See also Figures 1 to 3 When the opening 301 of the isolation chamber 300 is pressed below the liquid level 501 of the liquid 500, the gas inside the isolation chamber 300 will be subjected to the pressure of the liquid level 502 in the isolation chamber 300, so that the volume of the gas is reduced. In this case, the liquid level 502 in the isolation chamber 300 will move toward the inner side of the cavity of the isolation chamber 300. The cantilever beam probe 100 is arranged to extend toward the opening 301 of the isolation chamber 300, so that the liquid level 502 can first contact the needle tip 110 instead of the cantilever 120 during the rising process; by making the needle tip 110 not protrude from the opening 301, it can be avoided that the needle tip 110 contacts the liquid level 502 before the isolation chamber 300, so that when the position of the liquid level 502 in the isolation chamber 300 is adjusted later, the adjustable range is increased to avoid the liquid level 502 in the isolation chamber 300 from submerging the cantilever 120 or contacting the cantilever 120.
[0030] See also Figure 2 , Figure 3 When the opening 301 of the isolation cavity 300 is placed below the liquid level 501 of the liquid 500, under the action of the gas inside the cavity of the isolation cavity 300, the liquid level 502 inside the isolation cavity 300 will be close to the opening 301, and in some cases, it will be lower than the liquid level 501 outside the isolation cavity 300. In this case, at least one of the amount of gas in the isolation cavity 300 and the volume inside the isolation cavity 300 can be adjusted by the adjusting device 400, so that the liquid level 502 inside the isolation cavity 300 rises or falls, and then the relative position of the liquid level 502 and the cantilever beam probe 100 is adjusted. For example, at least one of the amount of gas in the isolation cavity 300 and the volume inside the isolation cavity 300 can be adjusted by the adjusting device 400, so that the position of the liquid level 502 inside the isolation cavity 300 changes, and the relative position of the liquid level 502 inside the cantilever beam probe 100 is adjusted. Figure 2 The liquid level 502 shown in FIG. 1 is separated from the needle tip 110, and the liquid level 502 is adjusted to Figure 3 The liquid level 502 shown in FIG. 5 is not above the tip of the needle tip 110; or Figure 3 The situation shown is adjusted to Figure 2 The situation shown.
[0031] By using the adjustment device 400 to adjust the position of the liquid level 502, on the one hand, the liquid level 502 can be prevented from submerging the cantilever 120 of the cantilever beam probe 100, and the cantilever 120 of the cantilever beam probe 100 can be prevented from entering the liquid 500 environment and causing interference with the detection. On the other hand, the tip of the needle tip 110 of the cantilever beam probe 100 can be kept in the liquid environment during vibration, so as to avoid the tip of the needle tip 110 repeatedly entering and exiting the liquid environment, causing changes in its force and causing interference with the detection.
[0032] In some cases, it is necessary to analyze the stress condition of the needle tip 110 by detecting light irradiated to the cantilever 120 of the cantilever beam probe 100 and the light reflected by the cantilever 120. At this time, a corresponding light-transmitting window 320 can be set in the isolation cavity 300, so that the light L from the outside of the isolation cavity 300 can pass through the light-transmitting window 320 to illuminate the cantilever 120, and the light L reflected by the cantilever 120 can pass through the light-transmitting window 320 to the outside of the isolation cavity 300 and be received by the corresponding receiver, and then the position and force of the needle tip 110 can be analyzed through the vibration state of the cantilever 120.
[0033] See also Figure 1 When the tip 110 side of the cantilever beam probe 100 is the front side, the light-transmitting window 320 can be set on the cavity of the isolation cavity 300 corresponding to the back side of the cantilever beam probe 100. The light-transmitting window 320 can be made of a transparent material. It should be noted that the light-transmitting window 320 needs to be in a closed but light-transmitting form, so that when the opening 301 of the isolation cavity 300 is closed by the liquid level 502 of the liquid 500, the inner side of the cavity of the isolation cavity 300 forms a closed cavity C, so as to facilitate the adjustment of the adjustment device 400.
[0034] For the regulating device 400, when the regulating device 400 is capable of adjusting the amount of gas in the isolation chamber 300, the regulating device 400 can be set as a ventilation switch 410, so that one end of the ventilation switch 410 is connected to the inner side of the isolation chamber 300, and the other end is connected to the gas environment or gas source outside the isolation chamber 300.
[0035] For the ventilation switch 410, since the atomic force microscope probe provided by the present invention is usually small in size and usually difficult to accommodate commonly used devices such as air valves, the ventilation switch 410 can use a piezoelectric valve and integrate the piezoelectric valve on the wall of the isolation cavity 300; or, an air hole 302 is set on the wall of the isolation cavity 300, and the air hole 302 is connected to an external air valve or source through components or structures such as pipelines.
[0036] When the ventilation switch 410 is able to control the connection and separation between the inside of the isolation chamber 300 and the external gas environment, by opening the ventilation switch 410, the gas inside the isolation chamber 300 is gradually discharged to the outside of the isolation chamber 300 under the action of pressure, thereby causing the liquid level 502 inside the isolation chamber 300 to gradually rise, and when the liquid level 502 contacts the needle tip 110 to a certain extent, the ventilation switch 410 is closed so that the liquid level 502 no longer continues to rise.
[0037] When the ventilation switch 410 is capable of controlling the connection and separation between the inside of the isolation chamber 300 and the external gas source, the ventilation switch 410 can be turned on to discharge the gas inside the isolation chamber 300 to the outside of the isolation chamber 300 through the external gas source, or the ventilation switch 410 can be turned on to allow the gas outside the isolation chamber 300 to enter the inside of the isolation chamber 300 through the external gas source, and the height of the liquid level 502 inside the isolation chamber 300 is increased or decreased accordingly to adjust the relative position of the liquid level 502 and the needle tip 110 of the cantilever beam probe 100. Accordingly, when an external gas source is provided, the ventilation switch 410 can be provided on the isolation chamber 300, in the external gas source, or in the pipeline between the isolation chamber 300 and the external gas source.
[0038] In addition, the regulating device 400 may further include a volume adjusting device 420, which is configured to at least change the form of the cavity wall of the isolation cavity 300. Figure 4 , shows a form in which a volume adjustment device 420 is provided on an isolation chamber 300, wherein the volume adjustment device 420 includes a piezoelectric block 421 and a deformable plate 422. The two ends of the piezoelectric block 421 are fixed so that the piezoelectric block 421 can change between bending and straightening by adjusting the power-on state, or can change the degree of bending. The piezoelectric block 421 is close to the deformable plate 422, so that when the piezoelectric block 421 is bent, it can contact and abut against the deformable plate 422, so that the shape of the deformable plate 422 changes. Please refer to Figure 5 , shows a feasible configuration of the volume adjustment device 420, wherein a window is provided on the side wall 303 of the isolation chamber 300, and the volume adjustment device 420 is installed on the window to seal the window; the isolation chamber 300 and the deformable plate 422 of the solvent adjustment device 420 together enclose the space inside the isolation chamber 300. It should be noted that the projection of the piezoelectric block 421 on the deformable plate 422 is smaller than the size of the deformable plate 422, so that the two sides of the piezoelectric block 421 are connected to each other and are in the same cavity C.
[0039] See also Figure 5 , Figure 6 , respectively showing the volume adjustment device 420 in two states. Figure 5 In the state shown, the piezoelectric block 421 of the volume adjustment device 420 is not in contact with the deformation plate 422. At this time, the volume inside the cavity of the isolation cavity 300 is in the first state. Figure 6In the state shown, the piezoelectric block 421 of the volume adjustment device 420 is deformed under the action of the control voltage. Since the two ends of the piezoelectric block 421 are fixed, the piezoelectric block 421 forms a curved shape. The curved piezoelectric block 421 pushes the deformed plate 422 toward the outside of the cavity of the isolation cavity 300, so that the volume of the cavity of the isolation cavity 300 increases. When one side of the opening 301 of the isolation cavity 300 is covered by the liquid level 502, the volume of the isolation cavity 300 increases, and the amount of gas remains unchanged, which will cause the liquid level 502 to rise.
[0040] In summary, the volume adjustment device 420 can increase or decrease the volume inside the isolation chamber 300, thereby increasing or decreasing the liquid level 502 in the isolation chamber 300, and further adjusting the relative position between the liquid level 502 and the cantilever beam probe 100. For the adjustment process and objectives of the relative position between the liquid level 502 and the cantilever beam probe 100, please refer to the aforementioned content, which will not be repeated here.
[0041] In addition, the present invention also provides a method for using an atomic force microscope, using the aforementioned underwater atomic force microscope probe. Specifically, the method comprises the following steps: S1: Fill the isolation chamber 300 with gas, and make the opening of the isolation chamber 300 go down into the liquid surface 501. The isolation chamber 300 can be filled with gas by first placing the isolation chamber 300 in a gas environment, and then buckling the opening of the isolation chamber 300 downward to the liquid surface 501 to ensure that there is gas in the isolation chamber 300.
[0042] S2: The position of the liquid level 502 in the isolation chamber 300 is adjusted by the adjusting device 400 so that the cantilever beam probe 100 is in a state where the needle tip 110 enters the liquid surface and the cantilever 120 does not enter the liquid surface.
[0043] S3: Use the cantilever beam probe to detect the object under test.
[0044] When the needle tip of the cantilever beam probe 110 enters the liquid surface and the cantilever 120 does not enter the liquid surface, on the one hand, when the needle tip 110 vibrates, the needle tip 110 and the liquid surface 502 can at least maintain contact with the liquid surface 502 due to the surface tension of the liquid, thereby avoiding the needle tip 110 from frequently entering and exiting the liquid surface 502, and / or avoiding the frequent breaking and reconstruction of the liquid bridge between the needle tip 110 and the liquid surface 502, thereby reducing or avoiding the influence of the interaction force between the liquid surface 502 and the needle tip 110; on the other hand, the cantilever 120 is always located in the gas environment outside the liquid surface 502, avoiding the formation of too many resonance peaks due to the cantilever 120 in the liquid 500, making the main peak of the resonance frequency easy to identify, and can improve the accuracy of determining the resonance frequency by about 10 times, and can also avoid the difficulty of moving the cantilever beam probe 100 during the scanning process, can conveniently and clearly determine the resonance frequency, and facilitate the scanning of the object to be measured.
[0045] Therefore, by using the solution provided by the present invention, the problems of difficulty in determining the resonance frequency of the probe cantilever, low imaging quality and difficulty in imaging when the probe cantilever is in a liquid environment can be effectively solved, thereby greatly improving the AFM detection effect on the object being measured in the liquid.
[0046] In some cases, in order to make the gas in the isolation chamber 300 easier to control, when the opening 301 of the isolation chamber 300 is below the liquid level 501, the first plane S1 can be made parallel to the liquid level 501, so that the opening 301 is parallel to the liquid level 502, so as to prevent the gas in the isolation chamber 300 from overflowing to the outside of the isolation chamber 300.
[0047] In addition, due to the probe and the use method provided by the present invention, the relative position of the cantilever beam probe 100 and the liquid surface 502 can be adjusted by the adjustment device 400. Even if the cantilever beam probe 100 is replaced and an installation error occurs, or the probe is tilted and enters the liquid, etc., the position of the liquid surface 502 can still be adjusted by the adjustment device 400, and the needle tip 110 and the liquid surface 502 are adjusted accordingly to meet the detection requirements; accordingly, there is no need to make the opening 301 of the isolation cavity 300 completely parallel to the liquid surface 501 of the liquid 500 and contact the liquid surface 501, the operating accuracy requirement for replacing the cantilever beam probe 100 is reduced, and there is no need to perform additional calibration of the cantilever beam probe 100, so that the operating difficulty is greatly reduced, the use is convenient, and the use efficiency of the AFM and the detection efficiency of the object to be measured in the liquid are greatly improved.
[0048] Specifically, in S2, it can be determined that the cantilever beam probe 100 is in a state where the needle tip 110 enters the liquid surface 502 and the cantilever 120 does not enter the liquid surface 502 by the following method: A201: Separate the tip 110 of the cantilever beam probe 100 from the liquid surface 502; drive the tip 110 of the cantilever beam probe 100 to vibrate through the piezoelectric actuator 200; A202: adjusting at least one of the amount of gas in the isolation chamber 300 and the volume of the isolation chamber by the adjusting device 400, so that the liquid level 502 in the isolation chamber 300 gradually rises, and detecting the force applied to the needle tip 110 at the same time; A203: When the force on the tip 110 of the cantilever beam probe 100 changes suddenly for the first time, stop the adjusting device 400.
[0049] In A202, under normal circumstances, the needle tip 110 is adjusted by gradually approaching the liquid surface 502 and entering the liquid surface 502 to ensure that the cantilever 120 does not contact the liquid surface 502 and to prevent the cantilever 120 from being attached to the surface of the liquid, thereby avoiding interference with the detection. Of course, in some cases, the relative position of the liquid surface 502 and the needle tip 110 can also be adjusted during the scanning process by gradually lowering the liquid surface 502 in the isolation chamber 300.
[0050] Since the needle tip 110 approaches the liquid surface 502 and contacts the liquid surface 502 during the vibration process, the process in which the needle tip 110 gradually approaches the liquid surface 502 and contacts the liquid surface 502 can generally include the following situations: the needle tip 110 approaches the liquid surface 502; the needle tip 110 contacts the liquid surface 502 for the first time when it vibrates to a position close to the liquid surface 502, and forms a liquid bridge under the tension of the liquid surface 502, so that when the needle tip 110 vibrates to a position away from the liquid surface 502, the needle tip 110 and the liquid surface 502 remain in contact; the needle tip 110 further enters the liquid surface 502, and in some cases, the liquid bridge no longer appears within the amplitude range of the needle tip 110; when the needle tip 110 approaches the surface of the object to be measured, an interaction force is generated between the surface of the object to be measured and the needle tip 110, and in this case, scanning of the object to be measured can be started.
[0051] Therefore, for A203, when the force on the tip 110 of the cantilever beam probe 100 changes suddenly for the first time, it indicates that the tip 110 of the surface probe enters the liquid surface 502. At this time, the adjusting device 400 is stopped to keep the relative position between the tip 110 of the cantilever beam probe 100 and the liquid surface 502 substantially unchanged, so that the cantilever beam probe 100 is in a state where the tip 110 enters the liquid surface and the cantilever 120 does not enter the liquid surface.
[0052] Specifically, in some cases, after the first sudden change in the force on the needle tip 110, the cantilever 120 may also contact the liquid surface 502 due to the rise of the liquid level 502. At this time, the liquid level 502 will interfere with the reflection of the detection light L by the cantilever 120, resulting in the inability to obtain the vibration signal of the cantilever beam probe 100, and the inability to detect the force on the needle tip 110. Therefore, after the first sudden change in the force on the needle tip 110 is detected, if the force on the needle tip 110 cannot be detected, it indicates that the cantilever 120 is also in contact with the liquid surface 502. At this time, it is necessary to stop the detection, move out the probe, adjust the corresponding components of the probe, the position of the object to be measured, or adjust the detection steps, etc., and re-run A201-A203.
[0053] Specifically, in S3, the detection of the object to be detected can be achieved in the following manner: A301: driving the tip 110 of the cantilever beam probe 100 to vibrate through the piezoelectric actuator 200; A302: moving the underwater atomic force microscope probe to change the relative position between the tip 110 of the cantilever beam probe 100 and the object to be measured, for example, gradually bringing the tip 110 closer to the object to be measured; when the interaction force between the tip 110 of the cantilever beam probe 100 and the object to be measured reaches a preset condition, stopping moving the underwater atomic force microscope probe; A303: Use the cantilever beam probe 100 to detect the object under test.
[0054] The preset condition described in A302 can be set to detect a second sudden change in the force on the needle tip 110 , at which time it can be considered that an interaction force that can be used to detect the object to be measured occurs between the needle tip 110 of the cantilever beam probe 100 and the object to be measured.
[0055] In S3, different positions on the surface of the object to be measured can be detected in sequence by moving the cantilever beam probe 100 along a preset direction, thereby realizing scanning of the object to be measured. The preset direction can be set as needed, and in most cases, the preset direction mainly refers to the moving direction of the cantilever beam probe 100 in a direction substantially parallel to the liquid surface 501; during the scanning process, the cantilever beam probe 100 can also move in a direction substantially perpendicular to the liquid surface 501 according to the characteristics of the surface morphology of the object to be measured, so as to ensure effective detection of the surface of the object to be measured.
[0056] The cantilever probe 100 can be moved by keeping the position of the isolation cavity 300 unchanged to move the position of the cantilever probe 100, or by moving the probe provided by the invention as a whole to move the cantilever probe 100. As a more feasible solution, the aforementioned underwater atomic force microscope probe can be moved along a preset direction, thereby moving the cantilever probe 100 along the preset direction.
[0057] The above shows and describes the basic principles, main features and advantages of the present invention, so the above is only an embodiment of the present invention. It should be understood by those skilled in the art that the present invention is not limited by the above embodiments, and the above embodiments and descriptions only describe the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention also includes various equivalent changes and improvements, which will fall within the scope of the present invention to be protected.
Claims
1. A probe for an underwater atomic force microscope, characterized in that: The invention comprises a cantilever beam probe, a piezoelectric actuator, an isolation cavity, and an adjusting device. The isolation cavity is a hollow cavity opening along a first plane. The cantilever beam probe arranged in the isolation cavity extends toward the opening and its needle tip does not protrude from the opening. The cantilever beam probe vibrates under the action of the piezoelectric actuator. The adjusting device is constructed in a form capable of adjusting at least one of the amount of gas in the isolation cavity and the volume of the isolation cavity.
2. The underwater atomic force microscope probe as claimed in claim 1, characterized in that: The isolation cavity is provided with a light-transmitting window, and the light-transmitting window is configured to allow light passing through the light-transmitting window to irradiate the cantilever beam probe, and / or allow a light beam reflected by the cantilever beam probe to be emitted outside the isolation cavity through the light-transmitting window.
3. The underwater atomic force microscope probe as claimed in claim 1, characterized in that: The regulating device comprises a ventilation switch, one end of which is communicated with the inner side of the isolation chamber, and the other end of which is communicated with the external gas environment or gas source of the isolation chamber.
4. The underwater atomic force microscope probe as claimed in claim 1, characterized in that: The regulating device comprises a volume adjusting device, and the volume adjusting device is configured to at least change the form of the cavity wall of the isolation cavity.
5. A method for using an atomic force microscope, using the submersible atomic force microscope probe according to any one of claims 1 to 4, characterized in that: The steps include: S1: Fill the isolation chamber with gas and allow the opening of the isolation chamber to enter the liquid surface downward; S2: adjusting the liquid level position in the isolation chamber by the adjusting device so that the cantilever beam probe is in a state where the needle tip enters the liquid surface and the cantilever does not enter the liquid surface; S3: Use the cantilever beam probe to detect the object under test.
6. A method for using an atomic force microscope as claimed in claim 5, characterized in that: In S2, the cantilever beam probe is placed in a state where the tip of the cantilever beam probe enters the liquid surface and the cantilever beam does not enter the liquid surface by: A201: separating the tip of the cantilever beam probe from the liquid surface; driving the tip of the cantilever beam probe to vibrate by the piezoelectric actuator; A202: adjusting at least one of the amount of gas in the isolation chamber and the volume of the isolation chamber by the adjustment device so that the liquid level in the isolation chamber gradually rises, and detecting the force applied to the needle tip at the same time; A203: When the force on the tip of the cantilever beam probe changes suddenly for the first time, stop the adjusting device.
7. A method for using an atomic force microscope as claimed in claim 5, characterized in that: The S3 further includes: A301: driving the tip of the cantilever beam probe to vibrate by the piezoelectric actuator; A302: moving the underwater atomic force microscope probe, and stopping moving the underwater atomic force microscope probe when the interaction force between the tip of the cantilever beam probe and the object to be measured reaches a preset condition; A303: Use a cantilever beam probe to detect the object under test.
8. A method for using an atomic force microscope as claimed in claim 7, characterized in that: In A303: the object to be measured is scanned by moving the cantilever beam probe along a preset direction to detect the object to be measured.
9. A method for using an atomic force microscope as claimed in claim 8, characterized in that: The underwater atomic force microscope probe is moved along a preset direction, thereby moving the cantilever beam probe along the preset direction.
10. The method for using an atomic force microscope as claimed in claim 5, characterized in that: When the opening of the isolation chamber is below the liquid surface, the first plane is parallel to the liquid surface.