Needle point frame for atomic force microscope

Abstract

The utility model discloses a needle point frame used for an atomic force microscope, comprising a detachable support, the bottom surface of the detachable support is provided with an installation pedestal, the bottom surface of the installation pedestal is provided with an inclined installation surface, the inclined installation surface is provided with a positioning installation groove, the positioning installation groove is internally provided with a probe, and the probe is arranged on the installation pedestal. The probe is pressed and fixed in the positioning installation groove through a pressing sheet, one end, with a needle point, of the probe extends out of the positioning installation groove and is suspended, the pressing sheet is connected with the detachable support through a screw, and an avoiding hole is formed in the position, corresponding to the needle point part of the probe, of the detachable support. The probe is convenient to install and replace, the operation difficulty is low, and the use is convenient and reliable.

Description

Technical Field

[0001] This utility model relates to the field of atomic force microscopy technology, and specifically to a tip holder for atomic force microscopy. Background Technology

[0002] Atomic force microscopy (AFM) is an important instrument for analyzing surface morphology and electromagnetic properties with atomic resolution. It requires the interaction force between the tip of the microcantilever (the microcantilever and the tip together form a probe) and the sample surface to detect the surface morphology and physical properties of the sample.

[0003] The probe is mounted on the AFM device and fixed downwards, so it needs to be placed upwards during installation, which greatly reduces the convenience of operation. In contact mode, the probe tip is prone to passivation or breakage when scanning hard samples. The coating is easily corroded in liquid environment, reducing its lifespan. Therefore, the probe often needs to be replaced. The upward operation method can easily cause the probe to fall into the gap of the lower device, and the installation of new probes is more difficult.

[0004] Furthermore, when probes need to be transferred between different devices, the probe disassembly and installation process can easily cause contamination or mechanical damage. Summary of the Invention

[0005] The technical problem to be solved by this utility model is to provide a tip holder for atomic force microscopes, which is convenient for installing and replacing probes, has low operation difficulty, and is convenient and reliable to use.

[0006] To address the aforementioned technical problems, this utility model provides a tip holder for an atomic force microscope, comprising a detachable support, a mounting base on the bottom surface of the detachable support, an inclined mounting surface on the bottom surface of the mounting base, a positioning mounting groove on the inclined mounting surface, a probe disposed within the positioning mounting groove, the probe being pressed and fixed within the positioning mounting groove by a pressure plate, one end of the probe with a tip extending out of the positioning mounting groove and suspended in the air, the pressure plate being connected to the detachable support by screws, and an avoidance hole provided on the detachable support corresponding to the tip portion of the probe.

[0007] Furthermore, the surface of the pressure plate is provided with a waist-shaped hole, the screw passes through the waist-shaped hole and is connected to the detachable bracket, and a limiting groove is provided on the detachable bracket corresponding to the end of the pressure plate away from the probe, and a spring is provided in the limiting groove, the spring abutting against the end of the pressure plate.

[0008] Furthermore, a guide protrusion is provided on the detachable bracket around the limiting groove, and a bent edge is provided on both sides of the pressure plate corresponding to the guide protrusion. The two bent edges cooperate with the guide protrusion to restrict the movement direction of the pressure plate.

[0009] Furthermore, a lead-out groove is provided on the detachable bracket on one side of the limiting groove. The lead-out groove is connected to the limiting groove. An electrical contact metal piece is provided in the lead-out groove. The electrical contact metal piece extends into the limiting groove and abuts against the spring.

[0010] Furthermore, the pressure plate has a bending portion on one side of the probe, and the pressure plate presses and fixes the probe through the bending portion.

[0011] Furthermore, a piezoelectric ceramic is provided between the detachable bracket and the mounting base.

[0012] Furthermore, the detachable bracket is provided with a pull handle and a circuit module at both ends, the circuit module being used for power supply and signal transmission, and dovetail slides are provided on both sides of the detachable bracket.

[0013] Furthermore, clearance recesses are provided on both sides of the positioning mounting groove.

[0014] The beneficial effects of this utility model are:

[0015] 1. The design of the detachable bracket allows the probe to be removed from the AFM device for disassembly and installation. This changes the method of disassembling and installing smaller probes upwards in narrow spaces to disassembling and installing probes downwards in larger spaces, greatly improving convenience and reducing the difficulty of operation.

[0016] 2. The probe is installed by clamping and fixing with a pressure plate. When disassembling, simply loosen the pressure plate to further improve the ease of disassembly. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0018] Figure 2 This is a schematic diagram of the bottom structure of this utility model;

[0019] Figure 3 This is a schematic diagram of the tablet clamping and installation structure of this utility model;

[0020] Figure 4 This is a utility model Figure 3 Schematic diagram of the structure of the shielding area of ​​the intermediate pressure plate;

[0021] Figure 5 This is a partial structural cross-sectional schematic diagram of the present invention in use. Detailed Implementation

[0022] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments are not intended to limit the present invention.

[0023] Reference Figures 1 to 5 As shown, one embodiment of the tip holder for an atomic force microscope of the present invention includes a detachable bracket 1, a mounting base 2 provided on the bottom surface of the detachable bracket, an inclined mounting surface 3 provided on the bottom surface of the mounting base, a positioning mounting groove provided on the inclined mounting surface, a probe 5 provided in the positioning mounting groove, the probe being pressed and fixed in the positioning mounting groove by a pressure plate 6, the end of the probe with the tip extending out of the positioning mounting groove and suspended in the air, the pressure plate being connected to the detachable bracket by a screw 7, and an avoidance hole 8 provided on the detachable bracket corresponding to the tip part of the probe.

[0024] For probe installation, the detachable bracket does not need to be installed into the AFM device; instead, it is placed externally with the bottom facing upwards. The probe is then placed in the positioning mounting slot. Next, one end of the pressure plate abuts against the micro-cantilever surface of the probe, and the probe is mounted on the detachable bracket by pressing down with screws. The downward pressure of the screws ensures that the pressure plate holds the probe firmly within the positioning mounting slot, preventing it from moving. The angled mounting surface of the mounting base ensures that the probe extends obliquely downwards, as shown in the reference diagram. Figure 5 As shown, the probe extends beyond the bottom surface of the detachable bracket to avoid interference. The clearance hole is mainly used to avoid laser beam irradiation during equipment operation. The laser beam irradiates the back of the probe microcantilever and is reflected onto the photodiode array. When the microcantilever bends due to surface forces, the position of the reflected light spot changes accordingly, thus converting it into a measurable signal.

[0025] Once installed in place, the detachable bracket can be directly installed into the equipment. Specifically, the detachable bracket has a pull handle 18 and a circuit module 19 at each end. The pull handle facilitates the removal and installation of the detachable bracket, while the circuit module is used for power supply and signal transmission. The circuit module can be connected to the equipment via a plug-in connection. When the detachable bracket needs to be removed, the operation is convenient. Dovetail slides 20 are provided on both sides of the detachable bracket, and dovetail slides are provided at the corresponding positions on the equipment. The two work together to achieve quick plug-in and plug-out installation.

[0026] AFM has three main core imaging modes:

[0027] 1. Contact mode: The probe maintains soft contact with the sample surface, relying on the mutual repulsion between the atoms at the probe tip and the atoms on the sample surface.

[0028] 2. Non-contact mode: The probe scans within a distance of 5-20 nanometers above the sample, avoiding direct contact, and is suitable for samples that are not easily deformed.

[0029] 3. Tapping mode: The probe taps lightly on the sample surface, which can maintain high resolution while reducing damage to the sample.

[0030] When the tapping mode is required, external vibration is needed for the probe to tap. Therefore, a piezoelectric ceramic 17 is provided between the detachable bracket and the mounting base. The piezoelectric ceramic is energized and starts to vibrate, which in turn causes the mounting base to vibrate, and thus the probe vibrates as well.

[0031] Since vibrations are transmitted to the end of the pressure plate pressing against the probe and mounting base, the pressure plate also vibrates. This vibration affects the probe's vibration, so vibration damping of the pressure plate is necessary to ensure the vibration provided by the piezoelectric ceramic meets requirements. Specifically, a slotted hole 9 is provided on the surface of the pressure plate. A screw passes through the slotted hole and connects to a detachable bracket. A limiting groove 10 is provided on the detachable bracket at the end of the pressure plate furthest from the probe. A spring 11 is installed in the limiting groove, and the spring abuts against the end of the pressure plate. When the screw is locked, the pressure plate is not directly contacted and fixed to the detachable bracket. Instead, it is fixed by the reaction force at both ends of the pressure plate combined with the downward pressure of the screw. When the probe vibrates, the probe and mounting base cause one end of the pressure plate to resonate, while the middle of the pressure plate is suspended and pressed by the screw. The other end abuts against the spring. The vibration is effectively canceled out by the spring after transmission. Ultimately, the end of the pressure plate moves synchronously with the vibration of the probe and mounting base, without generating additional vibration or aftershocks that would affect the probe's vibration.

[0032] To further improve the ease of disassembly, guide protrusions 12 are provided on the detachable bracket around the mounting limiting groove. Bent edges 13 are provided on both sides of the pressure plate corresponding to the guide protrusions. These two bent edges, in conjunction with the guide protrusions, restrict the movement direction of the pressure plate. That is, after the pressure plate is axially limited by the screw, it can only move along the length of the oblong hole, i.e., towards or away from the probe. When it is necessary to disassemble and install the probe, first loosen the screw to allow the pressure plate to move freely. Move the pressure plate to the rear end so that the end of the pressure plate does not cover the positioning mounting groove. Then, use tweezers or other tools to remove the probe and replace it with a new one. Next, move the pressure plate in the opposite direction to move the end of the pressure plate to the probe surface. Then, turn the screw to press the pressure plate firmly. The pressure plate applies the squeezing force of the screw to the probe, achieving fixation, and the pressure plate can no longer move, thus completing the probe replacement.

[0033] Since the probe needs to be biased during use, it can be energized on the pressure plate or the spring. However, since the pressure plate may be damaged and need to be replaced, and the spring may deform and move, which may easily lead to connection failure, this application provides a connection method. A lead-out groove 14 is also provided on the detachable bracket on one side of the limiting groove. The lead-out groove is connected to the limiting groove. An electric contact metal piece 15 is provided in the lead-out groove. The electric contact metal piece extends into the limiting groove and abuts against the spring. The electric contact metal piece is externally biased. The electric contact metal piece can be glued and fixed. One end of the spring abuts against the electric contact metal piece, and the other end abuts against the pressure plate, forming an effective passage.

[0034] The aforementioned pressure plate needs to be pressed onto the inclined surface. Therefore, a bending portion 16 is provided on the side of the pressure plate located on the probe. The pressure plate presses and fixes the probe tightly through the bending portion, which provides a larger contact area and ensures effective fixation. Furthermore, since the probe is very small, tools such as tweezers are required. To facilitate removing or placing the probe from or into the positioning mounting slot, clearance recesses 21 are provided on both side walls corresponding to the positioning mounting slot. The two ends of the tweezers are inserted into the two clearance recesses respectively, and then the probe can be removed by clamping it towards the center. Alternatively, after clamping the probe, it can be placed into the positioning mounting slot. Once the two ends of the tweezers are within the two clearance recesses, they can be released, and the probe is effectively positioned.

[0035] The above-described embodiments are merely preferred embodiments provided to fully illustrate the present invention, and the protection scope of the present invention is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art based on the present invention are all within the protection scope of the present invention.

Claims

1. A tip holder for an atomic force microscope, characterized by, The detachable support is provided with a mounting base on the bottom surface, the bottom surface of the mounting base is provided with an oblique mounting surface, the oblique mounting surface is provided with a positioning installation groove, and a probe is arranged in the positioning installation groove.

2. The tip holder for an atomic force microscope as recited in claim 1, wherein The probe is fixed in the positioning installation groove by a pressing sheet, one end of the probe with a needle tip extends out of the positioning installation groove and is suspended, the pressing sheet is connected with the detachable support through a screw, and the needle tip part of the probe is provided with an avoiding hole on the corresponding detachable support.

3. The tip holder for an atomic force microscope as recited in claim 2, wherein The surface of the pressing sheet is provided with a waist-shaped hole, the screw passes through the waist-shaped hole and is connected with the detachable support, the end of the pressing sheet away from the probe is provided with a limiting groove on the corresponding detachable support, a spring is arranged in the limiting groove, and the spring abuts against the end of the pressing sheet.

4. The tip holder for an atomic force microscope as recited in claim 2, wherein The periphery of the limiting groove is provided with a guide protrusion on the detachable support, the two sides of the pressing sheet are provided with a bending edge on the corresponding guide protrusion, and the two bending edges limit the moving direction of the pressing sheet in cooperation with the guide protrusion.

5. The tip holder for an atomic force microscope as recited in claim 1, wherein The detachable support is provided with a guide groove on one side of the limiting groove, the guide groove is connected with the limiting groove in a penetrating mode, an electrically connected metal sheet is arranged in the guide groove, the electrically connected metal sheet extends into the limiting groove and abuts against the spring.

6. The tip holder for an atomic force microscope as recited in claim 1, wherein The pressing sheet is provided with a bending part on the side of the probe, and the probe is fixed by the pressing sheet through the bending part.

7. The tip holder for an atomic force microscope as claimed in claim 1, wherein The detachable support is provided with a piezoelectric ceramic between the detachable support and the mounting base.

8. The tip holder for an atomic force microscope as claimed in claim 1, wherein The detachable support is provided with a pulling handle and a circuit module at two ends respectively, the circuit module is used for power supply and signal transmission, and dovetail sliding tables are arranged on the two sides of the detachable support. The two side walls of the positioning installation groove are provided with avoiding notches.

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